Image, data and code tools
Convert images, compress photos, and format JSON online.
douni.one is a free online toolbox for image conversion, image compression, JSON formatting and data conversion. Convert WebP to JPG or PNG, prepare CSV for a spreadsheet, or generate code from structured data. Choose a tool below; no account is required.
275 tools · 10 interface languages · No registration
Find a tool by taskStart with a useful tool
All tools
Find a tool by task
Image tools
Convert WebP files and compress images. Choose a compatible format and check transparency and quality before saving.
Merge images
Combine images into one PNG with horizontal or vertical layout, adjustable spacing and a transparent or colored background. Preview and download locally.
Flip image
Mirror a photo left to right or top to bottom and rotate it in 90° steps. Preview the result and save a PNG with transparency, entirely in your browser.
Add text to image
Add a caption to a photo using your device fonts. Set text size, color, position, opacity and outline, preview the image and download a PNG locally.
Invert colors
Invert the red, green and blue channels of a photo while preserving transparency. Preview a color negative and download the PNG without uploading.
Crop image
Crop a photo by dragging a rectangle or entering exact pixel coordinates. Preview the result and download a PNG locally.
Image mosaic
Apply a block mosaic to a rectangular part of a photo. Drag to select the region, adjust block size and preview the PNG.
SVG → PNG
Convert self-contained static SVG files into transparent PNG images. Batch conversion, output previews and ZIP downloads are supported.
Image → ICO
Convert an image into an ICO containing 16, 32, 48 and 256-pixel icons. Images are fitted proportionally with transparent padding.
JPG → WebP
Convert JPG or JPEG photos to WebP in your browser. Adjust quality, inspect previews and download files individually or as ZIP.
Resize images
Fit JPG, PNG, WebP or AVIF images inside a maximum width and height. Keep proportions and export PNG or JPG locally.
PNG → WebP
Convert static PNGs to WebP with a quality control, output previews and ZIP download. Files are processed on your device.
HEIC → JPG
Convert iPhone HEIC photos to JPG in your browser. Free batch conversion of up to 20 photos with ZIP download. Photos are not uploaded, and GPS/EXIF metadata is not kept.
HEIC → PNG
Convert HEIC/HEIF images to PNG locally in your browser. Keeps transparent areas and pixel dimensions, converts up to 20 files at once and saves them individually or as a ZIP.
WebP → JPG
Convert static WebP images to JPG for free in your browser on Windows, Mac, iPhone or Android. Choose JPEG quality and a background for transparent areas; convert up to 20 files and download individually or as a ZIP.
WebP → PNG
Convert static WebP images to PNG for free in your browser on Windows, Mac, iPhone or Android. Keeps transparency and pixel dimensions; convert up to 20 files and download them individually or as a ZIP.
AVIF → PNG
Convert static AVIF images to PNG in your browser. Preserve transparency and pixel dimensions, preview the result, and download individual images or a ZIP.
AVIF → JPG
Batch convert static AVIF images to JPG. Choose JPEG quality and a background for transparent areas, then download individual images or a ZIP.
Image → pixel art
Turn a photo into pixel art in your browser. Choose resolution, a 16-color retro or grayscale palette, and export a crisp PNG with an optional grid.
Image compression
Compress images in your browser. Adjust quality, dimensions and output format, compare file sizes, and save individual images or a ZIP.
PDF tools
Merge, split, rotate and convert PDFs, or create documents from images.
PNG → PDF
Convert PNG images into a PDF in your browser. Reorder pages, choose A4, Letter or image size, and preserve transparent pixels without uploading your files.
Merge PDF
Combine 2–20 PDFs into one document. Reorder files before merging; page content stays as PDF rather than images.
Split PDF
Select PDF pages by preview or page range. Save the selection as one PDF or export separate PDFs with a ZIP download.
PDF → JPG
Render selected PDF pages as JPG images at 72, 150 or 300 DPI. Preview each output and download individual images or a ZIP.
Rotate PDF
Rotate selected PDF pages by 90°, 180° or 270° and download a new PDF. Preview pages and process the file locally in your browser.
Delete PDF pages
Remove unwanted pages from a PDF using visual previews or page ranges. Keep the remaining pages in order and download the PDF without uploading it.
JPG → PDF
Convert up to 20 JPG images into one PDF. Reorder photos, choose A4, Letter or image size, set margins and download locally.
Encoders & decoders ↗
Encode and decode Base64, URLs, Unicode, binary text, JWTs and other common representations.
JavaScript Encoder / Decoder
JavaScript Encoder / Decoder. Local browser processing.
Email Obfuscator
Email Obfuscator. Local browser processing.
htpasswd Generator
htpasswd Generator. Local browser processing.
MySQL Password Hash
MySQL Password Hash. Local browser processing.
PostgreSQL MD5 Password Hash
PostgreSQL MD5 Password Hash. Local browser processing.
MariaDB Password Hash
MariaDB Password Hash. Local browser processing.
Bcrypt Generator
Bcrypt Generator. Local browser processing.
Bcrypt Verifier
Bcrypt Verifier. Local browser processing.
CRC-16 Hash Calculator
CRC-16 Hash Calculator. Local browser processing.
AES Encrypt / Decrypt
AES Encrypt / Decrypt. Local browser processing.
DES Encrypt / Decrypt
DES Encrypt / Decrypt. Local browser processing.
Escape Encoder / Decoder
Escape Encoder / Decoder. Local browser processing.
Keccak Hash Calculator
Keccak Hash Calculator. Local browser processing.
MD4 Hash Calculator
MD4 Hash Calculator. Local browser processing.
MD2 Hash Calculator
MD2 Hash Calculator. Local browser processing.
RSA / RSA2 Encrypt / Decrypt
RSA / RSA2 Encrypt / Decrypt. Local browser processing.
Scrypt Generator
Scrypt Generator. Local browser processing.
Scrypt Verifier
Scrypt Verifier. Local browser processing.
SHAKE Hash Calculator
SHAKE Hash Calculator. Local browser processing.
Cisco Type 7 Encoder / Decoder
Cisco Type 7 Encoder / Decoder. Local browser processing.
SM2 Encrypt / Decrypt
SM2 Encrypt / Decrypt. Local browser processing.
SM3 Hash Calculator
SM3 Hash Calculator. Local browser processing.
SM4 Encrypt / Decrypt
SM4 Encrypt / Decrypt. Local browser processing.
Punycode Encoder / Decoder
Punycode Encoder / Decoder. Local browser processing.
Token Random Generator
Token Random Generator. Local browser processing.
JSON Key Random Generator
JSON Key Random Generator. Local browser processing.
RC4 Encrypt / Decrypt
RC4 Encrypt / Decrypt. Local browser processing.
Rabbit Encrypt / Decrypt
Rabbit Encrypt / Decrypt. Local browser processing.
Hash Calculator
Hash Calculator. Local browser processing.
Triple DES (3DES) Encrypt / Decrypt
Triple DES (3DES) Encrypt / Decrypt. Local browser processing.
RIPEMD-160 Hash Calculator
RIPEMD-160 Hash Calculator. Local browser processing.
Base64url Encoder / Decoder
Convert UTF-8 text and URL-safe Base64. Encoding omits padding; decoding validates alphabet, padding and UTF-8.
Unicode Code Point Converter
Convert text to U+ code points and back. Reject surrogate values and code points above U+10FFFF.
Hex Byte Order Reverser
Reverse hex bytes as one sequence or within groups of 2, 4 or 8 bytes. Incomplete groups are rejected.
SHA Hash Generator
Hash UTF-8 text locally with SHA-1, SHA-2 or SHA-3. Whitespace and line breaks affect the digest.
JWT Decoder
Decode a JWT header and payload in your browser and inspect JSON claims without sending the token to a server.
Text to Binary Converter
Convert UTF-8 text into eight-bit binary byte groups or decode binary bytes back into readable text.
Text to Hex Converter
Convert UTF-8 text into hexadecimal bytes or decode hex pairs back to text, including Japanese characters and emoji.
JSON String Escape / Unescape
Encode text as a quoted JSON string literal or decode a JSON string, including quotes, backslashes and line breaks.
Base32 Encoder / Decoder
Encode UTF-8 text as RFC 4648 Base32 or decode Base32 to text.
Base58 Encoder / Decoder
Convert UTF-8 text to Base58 using the Bitcoin alphabet, or decode it.
HMAC Generator
Compute HMAC-SHA256, HMAC-SHA384 or HMAC-SHA512 for UTF-8 text and a key.
CRC32 Calculator
Calculate the CRC-32/ISO-HDLC checksum of UTF-8 text.
MD5 Text Hash
Calculate a hexadecimal MD5 digest from UTF-8 text locally.
GZIP Text Compressor
Compress UTF-8 text to Base64-encoded GZIP or decompress it back to text.
JWT Key Generator
Generate HMAC secrets, RSA key pairs or ECDSA key pairs locally.
Escape Regex Metacharacters
Escape regular-expression metacharacters so text can be used as a literal pattern.
Morse Code Translator
Translate Latin letters, numbers and supported punctuation into International Morse code, or decode dots and dashes.
Unicode Escape Converter
Encode text as UTF-16 Unicode escape sequences or decode backslash-u escapes, including supplementary characters.
ROT13 Text Converter
Apply ROT13 to Latin letters; apply it again to restore the original text.
URL Encoder / Decoder
Encode or decode a UTF-8 URL component for query values and path segments.
Base64 Encoder / Decoder
Encode UTF-8 text to Base64 or decode Base64 and Base64url to text.
HTML Escape / Unescape
Escape HTML special characters or decode basic and numeric HTML entities.
Random Password Generator
Random password generator for creating secure passwords to protect your accounts.
Text tools
Clean, compare, sort and reshape text, words and lines without uploading your input.
Text List Set Operations
Compare case-sensitive, nonempty lines using union, intersection, A minus B or symmetric difference.
Extract URLs from Text
Extract unique HTTP and HTTPS URLs from plain text. Remove trailing sentence punctuation; review paired brackets manually.
Shuffle Text Lines
Randomize up to 10,000 nonempty lines using Web Crypto and Fisher–Yates. Preserve duplicates and line contents.
Hiragana / Katakana Converter
Convert hiragana and katakana in either direction, including halfwidth katakana. Copy the result without uploading text.
Sort Lines
Sort text lines in ascending or descending natural order. Keep repeated lines and compare numbered items such as item2 and item10.
Reverse Text
Reverse Unicode text while keeping emoji families, combining marks and other grapheme clusters together.
Find and Replace Text
Replace every exact occurrence of a word or phrase in text. Preview, copy or download the edited result locally.
Remove Whitespace
Trim spaces around each line or remove all whitespace, including tabs and line breaks. Choose the cleanup you need.
HTML to Plain Text
Extract readable text from HTML, decoding entities and retaining common block breaks.
Markdown to Plain Text
Extract plain text from Markdown headings, emphasis, links and lists.
Naming Case Converter
Convert identifier words to camelCase, PascalCase, snake_case or kebab-case.
URL Slug Generator
Create a lowercase Unicode slug from a title, joining words with hyphens.
Add / Remove Line Numbers
Add 1-based line numbers or remove matching numeric prefixes.
Add Prefix / Suffix to Lines
Wrap every text line with a chosen prefix and suffix.
Text Frequency Counter
Count repeated whitespace-separated tokens with optional case folding.
Filter Text Lines
Keep or exclude text lines containing an exact phrase.
Remove Empty Lines
Delete empty or whitespace-only lines while preserving other text.
Extract Text Column
Extract a 1-based column from delimited text lines.
Wrap Text Lines
Wrap text to a chosen maximum grapheme count, preferring whitespace boundaries.
Indent / Unindent Text
Add spaces to every line or remove up to the selected number of leading spaces.
Truncate Text
Shorten text to a maximum number of grapheme clusters with a custom suffix.
Split Text into Chunks
Split text into chunks of a fixed number of Unicode grapheme clusters.
Clean Email List
Extract and deduplicate common ASCII email addresses from pasted text.
Character Counter
Count Unicode characters, words, lines and UTF-8 bytes in your browser.
Fullwidth / Halfwidth Converter
Convert fullwidth and halfwidth letters, numbers, spaces and Japanese katakana.
Uppercase / Lowercase Converter
Convert text to uppercase or lowercase and copy or download the result.
Remove Duplicate Lines
Remove duplicate text lines while keeping the first occurrence and original order.
Remove Line Breaks
Join multiline text by removing line breaks or replacing each with a space.
Text Diff Checker
Compare two texts line by line and highlight added and removed lines.
Date & time
Convert timestamps and time zones, compare dates and work with calendar formats.
Snowflake ID Decoder
Decode a 64-bit Snowflake ID into its timestamp, worker, process and sequence fields.
Unix Timestamp Converter
Live Unix clock and three converters: timestamp to date, date string to timestamp, and separate date fields, with seconds or milliseconds.
Business Day Calculator
Count Monday–Friday, excluding your listed holidays. No regional holiday calendar or weekend make-up workdays are assumed.
Date Difference Calculator
Count calendar days between two dates, with an option to include both endpoints. Leap years are handled automatically.
Age Calculator
Calculate completed years of age on a chosen reference date, including birthdays and leap-day births.
Duration Calculator
Add or subtract durations in HH:MM:SS format, including values longer than 24 hours and negative results.
Batch Timestamp Converter
Convert lines of Unix seconds or milliseconds to ISO dates, or reverse the conversion.
Timestamp Unit Converter
Convert seconds, milliseconds, microseconds and nanoseconds without integer precision loss.
Timestamp Difference Calculator
Subtract timestamp A from B and show the exact difference in the selected unit and seconds.
Time Zone Converter
Convert an ISO instant with an explicit offset into an IANA time zone.
Add / Subtract from Date
Add signed years, months, days, hours, minutes or seconds to an ISO instant.
ISO Week Date Converter
Convert Gregorian dates to ISO week-year, week and weekday and back.
Day of Year Converter
Convert dates to year-and-ordinal-day notation or restore dates from ordinal days.
Excel Serial Date Converter
Convert Excel serial dates in the 1900 or 1904 system to ISO UTC and back.
Windows FILETIME Converter
Convert Windows FILETIME 100-nanosecond ticks to ISO UTC and back without losing the sub-millisecond part.
Unix Timestamp Converter
Convert Unix seconds or milliseconds to UTC dates and ISO dates back to timestamps.
Calculators & units
Calculate percentages, fractions and statistics, or convert measurement units.
Random Integer Generator
Generate up to 10,000 integers using Web Crypto. Both bounds are included; repeats are allowed; range is signed 32-bit.
Scientific Notation Converter
Convert decimals and scientific notation using exact decimal text. Up to 10,000 input characters; exponent −10,000 to 10,000.
Bitwise Calculator
Compute AND, OR, XOR, NOT and shifts with arbitrary-size integers. Shift counts are 0–4096; negatives use signed semantics.
Roman Numeral Converter
Convert integers from 1 to 3999 into Roman numerals, or decode canonical Roman notation back to decimal.
Percentage Calculator
Calculate a percentage of a number, one number as a percentage of another, or the percentage change from A to B.
Ratio Simplifier
Reduce integer ratios and image aspect ratios to their simplest form using the greatest common divisor.
Fraction Calculator
Add, subtract, multiply or divide two fractions and get an exactly reduced fraction without floating-point rounding.
Data Size Converter
Convert bytes, decimal kB/MB/GB/TB and binary KiB/MiB/GiB/TiB. See the difference between 1000 and 1024-based units.
Length Converter
Convert meters, kilometers, centimeters, millimeters, inches, feet, yards and miles with one local calculation.
Temperature Converter
Convert Celsius, Fahrenheit and Kelvin. Check common temperatures such as boiling water and absolute zero.
Number List Statistics
Calculate count, sum, minimum, maximum, mean and median for a list of numbers.
Mass Unit Converter
Convert kilograms, grams, milligrams, tonnes, pounds and ounces.
Area Unit Converter
Convert square metric units, hectares, acres, square feet and square inches.
Volume Unit Converter
Convert liters, milliliters, cubic units, US gallons, US fluid ounces and imperial gallons.
Speed Unit Converter
Convert m/s, km/h, mph, ft/s and knots.
Angle Unit Converter
Convert degrees, radians, gradians and full turns.
Duration Unit Converter
Convert milliseconds, seconds, minutes, hours, days and weeks.
CSV & tables
Select and sort CSV columns and rows, calculate statistics, and convert table formats.
CSV to HTML Table
Convert a CSV header and equal-width rows into escaped HTML table markup, without rendering the input.
CSV to SQL INSERT
Generate PostgreSQL-compatible INSERT statements. All cells stay strings; headers must be simple, unique SQL identifiers.
Remove Duplicate CSV Rows
Keep the header and first occurrence of each complete CSV row. Compare cells exactly, including case and spaces.
CSV / TSV Converter
Convert comma-separated records to tab-separated records and back, preserving quoted cells and embedded line breaks.
CSV to Markdown Table
Convert CSV into a Markdown table with the first row as the header.
Transpose CSV
Swap the rows and columns of CSV data, including quoted cells.
Select CSV Columns
Select and reorder CSV columns using a comma-separated list of column numbers.
Sort CSV Rows
Sort CSV data rows naturally by a selected column, retaining the first row as a header.
CSV Column Statistics
Calculate statistics for a numeric CSV column, excluding its header.
JSON → CSV
Convert JSON objects to CSV locally. Select columns, flatten nested objects, choose delimiters and download UTF-8 CSV with optional BOM for Excel.
CSV → JSON
Convert CSV to JSON locally, including quoted commas and multiline cells. Read UTF-8 or Shift_JIS files and preserve leading zeros by default.
JSON tools
Format JSON, convert CSV and YAML, or generate types and schemas from API responses and configuration data.
JSON Diff Checker
Compare two JSON values by structure and show added, removed or changed values using JSON Pointer paths.
JSON to Typed XML Converter
Convert JSON into typed XML that preserves objects, arrays, nulls, booleans and arbitrary property names.
Sort JSON Keys
Sort object keys recursively while preserving array order and values.
JSON Merge Patch
Apply a JSON Merge Patch to a document and preview the merged result.
JSON Pointer Lookup
Find a value in a JSON document using an RFC 6901 pointer.
Flatten JSON
Flatten JSON leaves into an object keyed by JSON Pointer paths.
JSON to NDJSON
Convert a JSON array into one compact JSON value per line.
NDJSON to JSON
Combine newline-delimited JSON values into a formatted JSON array.
JSON to SQL INSERT
Generate a SQLite-compatible INSERT statement from JSON records.
JSON to Query String
Build URL query parameters from a JSON object, including repeated array values.
Query String to JSON
Convert URL query parameters into JSON, preserving repeated names as arrays.
Sort JSON Array
Sort a JSON array by a value selected with a JSON Pointer.
Filter JSON Array
Keep array items whose selected JSON Pointer value equals a supplied JSON value.
Remove JSON Array Duplicates
Deduplicate JSON array items by their full structure and keep the first occurrence.
JSON to Markdown Table
Turn an array of JSON objects into a Markdown table using the union of keys.
JSON to Python Literal
Convert JSON into a Python literal using True, False and None.
JSON to PHP Array
Convert JSON into PHP short-array syntax with quoted keys and scalar values.
Extract JSON Key Paths
List all object keys and array indices as JSON Pointer paths.
JSON Editor
Format, minify and edit JSON in a split-pane editor with a collapsible tree and exact number preservation.
JSON → React PropTypes
Convert JSON data to React PropTypes for efficient property type checking and code reuse in React projects.
JSON → Flow
Transform JSON structures into Flow types to enhance type safety and maintainability in JavaScript code.
JSON → GraphQL
Convert JSON to GraphQL schema for simplified API development and data management.
JSON → TypeScript
Generate TypeScript interfaces or type aliases from JSON online. Handles nested objects, arrays, null and optional fields, and runs in your browser.
JSON → MobX-State-Tree Model
Convert JSON to MobX State Tree models for optimized state management in complex applications.
JSON → Sarcastic
Transform JSON to Sarcastic types for enhanced type checking in JavaScript projects.
JSON → io-ts
Convert JSON to io-ts types to provide robust type theory support for TypeScript projects.
JSON → Rust Serde
An online REPL for converting JSON to Rust Serde structs, simplifying data serialization in Rust projects.
JSON → Mongoose Schema
Convert JSON to Mongoose schema for rapid MongoDB data model construction.
JSON → Big Query Schema
Transform JSON to BigQuery schema for optimized big data analysis and querying.
JSON → MySQL
Convert JSON to MySQL schema for simplified database design and data management.
JSON → Scala Case Class
Transform JSON to Scala case classes to enhance code clarity and maintainability in Scala projects.
JSON → Go Struct
Convert JSON to Go structs for easy data serialization and deserialization in Go projects.
JSON → Go Bson
Transform JSON to Go Bson format for optimized BSON data handling in Go projects.
JSON → YAML
Convert JSON to YAML format for simplified configuration file management and deployment.
JSON → JSDoc
Transform JSON to JSDoc comment format to enhance code documentation and readability in JavaScript projects.
JSON → Kotlin
Convert JSON to Kotlin data classes to improve type safety and code efficiency in Kotlin projects.
JSON → Java
Convert JSON to Java classes for simplified data model construction in Java projects.
JSON → JSON Schema
Convert JSON to JSON Schema format for optimized data validation and description in APIs.
JSON → TOML
Transform JSON to TOML format for simplified configuration file authoring and maintenance.
JSON → Zod Schema
Convert JSON to Zod schema for robust data validation support in TypeScript projects.
JSON formatter
Format JSON and JSON5 in your browser, check syntax errors, and copy standard JSON. Supports comments, single quotes and trailing commas without executing JavaScript.
JSON Schema → TypeScript
Convert JSON Schema to TypeScript definitions to help developers generate type-safe interfaces and data models.
JSON Schema → OpenAPI Schema
Transform JSON Schema to OpenAPI specifications for simplified creation and maintenance of RESTful API documentation.
JSON Schema → Protobuf
Convert JSON Schema to Protobuf definitions to facilitate the construction of efficient data serialization and network communication protocols.
JSON Schema → Zod Schema
Transform JSON Schema to Zod schema for robust data validation and type safety support in TypeScript projects.
JSON-LD → N-Quads
Convert JSON-LD data to N-Quads format for efficient storage and querying of RDF data.
JSON-LD → Expanded
Transform JSON-LD to expanded form for easier understanding and analysis of RDF graphs.
JSON-LD → Compacted
Convert JSON-LD to compacted form to optimize space usage and improve data processing efficiency.
JSON-LD → Flattened
Transform JSON-LD to flattened form to simplify complex RDF structures.
JSON-LD → Framed
Convert JSON-LD to framed form for data representation in specific contexts.
JSON-LD → Normalized
Transform JSON-LD to normalized form to ensure consistency and comparability of RDF data.
Formatters & config
Format code and convert XML, YAML, TOML, INI and environment configuration data.
XML Formatter
Indent well-formed XML for reading while preserving mixed text content and xml:space settings.
YAML Formatter
Parse and format YAML with two-space indentation while retaining document comments where supported.
TOML Formatter
Parse TOML and output consistently formatted tables and values.
CSS Formatter
Format CSS with consistent indentation using Prettier in your browser.
JavaScript Formatter
Format JavaScript and JSX with Prettier without executing the code.
HTML Formatter
Format HTML source with Prettier while preserving its parser’s whitespace semantics.
JSON to ENV
Convert a flat JSON object to quoted environment assignments.
ENV to JSON
Parse simple dotenv assignments into a JSON object of strings.
INI to JSON
Convert INI assignments and single-level sections to JSON string values.
JSON to INI
Convert a JSON object with scalar values and one level of sections into INI.
XML → JSON
Convert XML files to JSON format for easier data processing and analysis.
YAML → JSON
Transform YAML files to JSON format to achieve interoperability between different data formats.
YAML → TOML
Convert YAML to TOML for creating concise and easy-to-maintain configuration files.
TOML → JSON
Convert TOML to JSON in your browser: tables, arrays of tables and dates, with clear errors for duplicate keys and numbers JSON cannot hold. Handy for Cargo.toml, pyproject.toml and wrangler.toml.
TOML → YAML
Convert TOML to YAML to represent configuration data in a diverse manner.
HTML tools
Work with HTML, Pug, JSX, SVG components and CSS. Translate markup and styles for your next implementation.
SVG → JSX
Efficiently convert SVG files into React JSX code, streamlining the development process for dynamic and interactive web applications.
SVG → React Native
Leverage the power of React Native with this tool that converts SVG files into React Native components, enabling cross-platform mobile app development.
HTML → JSX
Transform HTML code into React JSX format for reuse and componentization within React projects, enhancing development efficiency and code quality.
HTML → Pug
Convert HTML to Pug (Jade) templates online. Choose fragment or full-document mode, tabs, attribute commas and quote style, and try examples for forms and documents.
Markdown → HTML
Transform Markdown files into HTML for displaying formatted text content on web pages.
CSS → JS Objects
Convert CSS files to JavaScript objects for easy use and manipulation of styles in front-end projects.
CSS → template literal
Transform object styles to template literals for optimized style application in frameworks like React.
CSS → TailwindCSS
Convert CSS to Tailwind CSS utility classes online. Paste CSS rules to get the matching classes as @apply, with rem base and configuration options (Tailwind v3 scale).
Less → CSS
Compile Less to CSS online with the official less.js compiler in your browser. Expands variables, nesting and mixins, with optional vendor prefixes — no lessc install needed.
Scss → CSS
Convert SCSS preprocessor files to standard CSS, simplifying the authoring and management of style sheets.
Sass → CSS
Convert Sass preprocessor files to standard CSS, enhancing the readability and reusability of style sheets.
JavaScript tools
Convert between TypeScript, JavaScript and Flow. Use the result as a starting point and verify it in your project.
JavaScript → JSON
Convert JSON5 object data to standard JSON in your browser. Supports unquoted keys, single quotes and comments; functions and JavaScript expressions are not executed.
TypeScript → Flow
Convert TypeScript code to Flow types for use in Flow projects.
TypeScript → TypeScript Declaration
Generate declaration files from TypeScript code to enhance maintainability.
TypeScript → JSON Schema
Transform TypeScript type definitions to JSON Schema for data validation and UI generation.
TypeScript → plain JavaScript
Convert TypeScript to JavaScript online: strip type annotations, interfaces and generics from .ts or .tsx code while keeping JSX. Babel-based conversion without type-checking or bundling.
TypeScript → Zod Schema
Convert TypeScript definitions to Zod Schema for improved type safety in data validation.
Flow → TypeScript
Convert Flow type definitions to TypeScript types, enabling the use of Flow's type safety features in TypeScript projects.
Flow → TypeScript Declaration
Transform Flow type definitions to TypeScript declaration files for improved modularity and maintainability of code.
Flow → plain JavaScript
Convert Flow code to plain JavaScript for use in environments that do not support Flow.
GraphQL
Generate types and client code from GraphQL schemas as a starting point for development.
GraphQL → TypeScript
Convert GraphQL schema to TypeScript definitions for type safety and autocompletion when using GraphQL in TypeScript projects.
GraphQL → Flow
Transform GraphQL schema to Flow types for enhanced type checking and accuracy when using GraphQL in Flow projects.
GraphQL → JAVA
Convert GraphQL schema to Java classes for implementing GraphQL APIs in Java backend services.
GraphQL → Resolvers Signature
Generate GraphQL resolver signatures to simplify the implementation of server-side GraphQL logic.
GraphQL → Introspection JSON
Generate introspection JSON from GraphQL schema for easy analysis and understanding of GraphQL architecture.
GraphQL → Schema AST
Convert GraphQL schema to an AST (Abstract Syntax Tree) for schema validation and transformation.
GraphQL → Fragment Matcher
Generate utilities for matching GraphQL fragments, optimizing data queries in the frontend GraphQL usage.
GraphQL → Components
Transform GraphQL schema into reusable React components for simplifying data acquisition and presentation in the UI layer.
GraphQL → TypeScript MongoDB
Generate TypeScript-compatible GraphQL schema for MongoDB databases, optimizing data modeling and API design.
Developer tools
Inspect URLs and network addresses, create hashes and IDs, work with JWT signatures and generate CSS.
HTTP Headers to JSON
Parse HTTP header lines into JSON arrays while preserving repeated header names.
Cookie Parser
Parse a request Cookie header. Keep duplicate names and optionally decode percent escapes.
UTM Campaign URL Builder
Build campaign links with source, medium and campaign. Preserve other query parameters and fragments.
robots.txt Generator
Generate one User-agent group with Allow, Disallow and an optional sitemap. Rules do not provide access control.
HTML Meta Tag Generator
Generate escaped title, description, canonical and Open Graph tags. Optional URLs must use HTTP or HTTPS.
Chmod Permission Calculator
Convert three-digit octal permissions and nine-character rwx notation. Special permission bits are not supported.
IPv4 Range to CIDR
Cover inclusive start and end IPv4 addresses with the smallest aligned CIDR blocks, without extra addresses.
Number Base Converter
Convert integers between bases 2 through 36, including binary, octal, decimal and hexadecimal, without precision loss.
HEX / RGB / HSL Converter
Convert a CSS color from HEX, RGB or HSL to all three formats and preview the resulting color.
UUID v4 Generator
Generate 1 to 100 random UUID version 4 identifiers using the browser cryptographic random generator.
URL Parser
Split an absolute URL into protocol, host, port, path, query parameters and fragment. Preserve repeated query parameter names.
IPv4 and Integer Converter
Convert dotted IPv4 addresses to unsigned 32-bit integers and back.
IPv4 Subnet Calculator
Calculate network, netmask, host range and address counts from IPv4 CIDR.
IPv6 Expand / Compress
Expand IPv6 into eight groups or compress its longest zero run.
CIDR and Netmask Converter
Convert an IPv4 prefix length into a dotted netmask and back.
JWT Generator and Signer
Create signed JWTs with HMAC, RSA, RSA-PSS or ECDSA using browser Web Crypto.
JWT Signature Verifier
Verify a JWT signature against an explicitly selected algorithm and trusted key.
JWT Claims Checker
Check exp, nbf, iat, issuer and audience against an explicit reference time and leeway.
URL Builder
Build an HTTP or HTTPS URL from a base, JSON query values and a fragment.
Extract URL Slug
Extract and percent-decode the last nonempty path segment of an absolute URL.
UUID Inspector
Inspect UUID text for its version, variant, nil and max values.
Color Contrast Checker
Calculate WCAG 2 contrast for two opaque sRGB HEX colors and check AA/AAA text thresholds.
PX / REM Converter
Convert pixels and rem units using an explicit root font size.
CSS Clamp Generator
Generate a fluid CSS clamp between two sizes and viewport widths.
Cadence → Go
Convert Cadence workflow descriptions to Go code for execution in Go environments.
QR Code Generator
Create custom QR codes for free. Generate QR codes easily in seconds.
Layout & Safe Areas
Explore screen layouts, safe areas and responsive spacing, then copy CSS for your project.
Before you start
Do my files leave my browser?
WebP conversion, image compression and JSON/CSV conversion run in your browser. Some other code converters use server processing. Check the tool description before working with confidential input.
Should I convert WebP to JPG or PNG?
Use JPG for photo compatibility, or PNG to keep a transparent background. JPG cannot store transparency. Both converters support batch processing and ZIP downloads.
What should I check when converting JSON and CSV?
Check identifiers such as 001, nested data and text encoding. JSON to CSV offers column selection and flattening; CSV to JSON supports Shift_JIS and preserving values as strings.
Which format should I choose?
WebP supports both lossy and lossless compression. A conversion changes the format; it does not restore detail already lost in the source image.
Google — WebPPNG uses lossless compression and supports an alpha channel for transparency. Choose PNG when you need to preserve a transparent background.
W3C — PNGJSON is a text format for structured data. Its values include objects, arrays, strings, numbers, booleans and null.
RFC 8259 — JSONCSV represents rows and fields as text. Fields containing commas, quotes or line breaks need quoting; a quote within a quoted field is doubled.
RFC 4180 — CSV
Content reviewed