Developer Tools
JSON, XML, HTML, CSS, JavaScript and SQL formatters and minifiers, Base64 and URL encoders, JWT decoder, hash generators and UUID tools.
102 free tools
JSON Formatter
Format, beautify and minify JSON online with 2-space, 4-space or tab indentation. Sort keys alphabetically and catch syntax errors instantly — free and private.
JSON Validator
Free online JSON validator: validate JSON and find syntax errors with the exact line and column. See root type, key counts and depth — instant and 100% private.
XML Formatter
Format and beautify XML online with proper indentation, or minify it to a single line. Parse errors are reported clearly — free, fast and fully private.
XML Validator
Free online XML validator and syntax checker: verify your XML is well-formed and read the parser's exact error, plus element and attribute counts. Private.
HTML Formatter
Format HTML online with clean, consistent indentation. This HTML formatter handles void elements and preserves pre, script and style exactly. Free and private.
HTML Minifier
Minify HTML online: strip comments, collapse whitespace between tags and shrink page size. See bytes saved instantly. Free, private, runs in your browser.
CSS Formatter
Format and beautify CSS online: one declaration per line, tidy indentation, spaces after colons and support for nested at-rules. Free and 100% private.
CSS Minifier
Minify CSS online: remove comments and whitespace, drop trailing semicolons and shorten hex colors. See bytes and percent saved. Free, instant, private.
JavaScript Formatter
Beautify JavaScript online with token-aware indentation. Respects strings, template literals, regex and comments. A quick, private, in-browser JS formatter.
JavaScript Minifier
Minify JavaScript online safely: strip comments and collapse whitespace without renaming or rewriting code. See bytes saved. Free and 100% in-browser.
SQL Formatter
Format SQL online: uppercase keywords, new lines before SELECT, FROM, WHERE and JOIN, indented AND/OR conditions. One-line minify included. Free and private.
Base64 Encoder
Encode text or files to Base64 instantly in your browser. UTF-8 safe, with a URL-safe Base64 option, copy and download. Free online Base64 encoder.
Base64 Decoder
Decode Base64 to readable text or download it as a file. Handles URL-safe base64url and missing padding automatically. Free, private, in-browser decoder.
URL Encoder
Percent-encode text for URLs instantly. Switch between encodeURIComponent and encodeURI modes, see live output and copy the result. Free URL encoder.
URL Decoder
Decode percent-encoded URLs back to readable text instantly. Optional '+ as space' handling for query strings and clear errors for malformed input.
JWT Decoder
Decode JWT header and payload instantly, with human-readable iat/exp/nbf timestamps and an expiry badge. Client-side only — tokens never leave your browser.
MD5 Hash Generator
Generate MD5 hashes of text or files instantly in your browser. 32-character hex checksum with uppercase option and one-click copy. Free and private.
SHA-1 Hash Generator
Compute SHA-1 hashes of text or files in your browser using Web Crypto. 40-character hex digest with uppercase option and instant copy. Free and private.
SHA-256 Hash Generator
Generate SHA-256 hashes of text or files with the browser's Web Crypto API. 64-character hex digest, uppercase option, instant copy. Free and private.
SHA-512 Hash Generator
Compute SHA-512 hashes of text or files right in your browser. 128-character hex digest with uppercase option and one-click copy. Free, fast, private.
UUID Generator
Generate 1–100 cryptographically random UUID v4 identifiers at once. Uppercase and hyphen-less options, per-item copy and copy-all. Free UUID generator.
Random Buffer Generator
Generate cryptographically secure random bytes at any size. Output as hex, Base64 or a downloadable binary file — perfect for keys, salts, tokens and test data.
Regex Tester
Test regular expressions online with live match highlighting, capture groups and flag toggles (g, i, m, s, u, y). Free, instant and 100% private in your browser.
Cron Expression Parser
Parse a cron expression, read it in plain English and see the next 5 run times. Validates all five fields instantly — free, private and runs in your browser.
String Escape / Unescape
Escape or unescape strings for JavaScript and JSON literals: quotes, backslashes, newlines, tabs and \uXXXX. Two-way, free and fully private in your browser.
HTML Entity Encoder
Encode text to HTML entities online: named entities for &, <, >, quotes plus numeric entities for the rest. Choose named or numeric — free and 100% private.
HTML Entity Decoder
Decode HTML entities back to plain text: named entities, &#nnn; decimal and &#xhh; hex references. Free, instant and processed entirely in your browser.
JSON Escape / Unescape
Escape or unescape JSON string values online, or stringify text into a quoted JSON string. Handles quotes, backslashes, newlines and \uXXXX. Free and private.
ASCII Table
Interactive ASCII table with decimal, hex, octal, binary, character and description for codes 0-127, plus optional extended 128-255. Searchable, free and private.
HTTP Status Code Lookup
Search HTTP status codes from 100 to 599 with name, category and clear description. Filter by number or text — a fast, free, private in-browser reference.
MIME Type Lookup
Look up MIME types by file extension and vice-versa with a solid map of common formats. Search by extension or content type — free, instant and private.
User Agent Parser
Parse a User-Agent string into browser, rendering engine, operating system and device type. Prefilled with your own UA — free, instant and private in the browser.
URL Parser
Parse a URL into protocol, host, port, path, query parameters and hash. Handles relative URLs with a base and shows query params in a table. Free and private.
Query String Parser
Parse a query string into editable key/value rows and build one back from rows. Handles repeated keys and arrays, two-way and live. Free and private in-browser.
JWT Generator
Generate and sign a JWT with HS256 using the Web Crypto API. Edit the header and payload JSON, add a secret, and get a signed token. Free and 100% private.
Basic Auth Header Generator
Generate an HTTP Basic Authorization header from a username and password, and decode a Basic header back to credentials. Free, instant and private in your browser.
Base32 Encode
Encode text to Base32 (RFC 4648) online with optional = padding. UTF-8 safe, instant and 100% private — your text never leaves the browser.
Base32 Decode
Decode Base32 (RFC 4648) back to readable text online. Validates the input, ignores padding and spaces, and flags bad characters. Free and 100% private.
Hex to Decimal
Convert hexadecimal to decimal online. Accepts an optional 0x prefix and handles arbitrarily large values with BigInt — free, instant and 100% in-browser.
Decimal to Hex
Convert decimal to hexadecimal online with uppercase and 0x-prefix toggles. Handles very large numbers exactly using BigInt. Free, instant and private.
Binary to Decimal
Convert binary to decimal online. Validates that the input is only 0s and 1s and handles very long binary strings exactly with BigInt. Free and private.
Decimal to Binary
Convert decimal to binary online with optional nibble grouping for readability. Handles very large numbers exactly with BigInt. Free, instant and private.
Code Case Converter
Convert an identifier between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case and Title Case — all forms at once. Free and private.
JSON Minify
Minify JSON online: strip all whitespace to shrink payloads. Validates first and shows the error line and column, plus size before and after. Free and private.
JSON Sort Keys
Sort JSON object keys alphabetically online, recursively through nested objects, and pretty-print the result. Validates input first. Free, instant and private.
ULID Generator
Generate ULIDs online: 128-bit, lexicographically sortable IDs with a 48-bit timestamp and 80 bits of randomness. Create up to 50 at once. Free and private.
NanoID Generator
Generate NanoIDs online with a configurable size and alphabet. Uses crypto-secure, unbiased random sampling. Create up to 50 URL-safe IDs at once. Free and private.
CRC-32 Generator
Compute the CRC-32 (IEEE 802.3) checksum of text online and see it as hex and unsigned decimal. Great for integrity checks. Free, instant and 100% private.
JSON to Query String
Convert a flat JSON object to a URL query string online. Values are percent-encoded and arrays become repeated keys. Validates the JSON first. Free and private.
Query String to JSON
Convert a URL query string (or full URL) to a JSON object online. Repeated keys become arrays and values are decoded. Pretty-printed output. Free and private.
Binary to Text Converter
Convert binary code back to readable text online. Decodes space-separated or continuous 8-bit binary as UTF-8, so accents and emoji survive. Free and private.
Hex to Binary Converter
Convert hexadecimal to binary online with 4-bit or 8-bit grouping and zero-padding to 8, 16, 32 or 64 bits. Handles 0x prefixes and long values. No upload.
Binary to Hex Converter
Convert binary to hexadecimal online. Separators are ignored, bits are padded to whole nibbles, with uppercase and 0x prefix options. Fast, free and private.
Octal to Decimal Converter
Convert octal to decimal online and see the working — each digit multiplied by its power of 8 in a step-by-step table. Handles huge values exactly. Free tool.
Decimal to Octal Converter
Convert decimal to octal online with the repeated-division-by-8 working shown row by row. Exact for huge integers, negatives supported. Free and private.
Base64URL Encoder
Encode text to URL-safe Base64URL online — the JWT variant with - and _ instead of + and /, no padding. UTF-8 aware, instant and 100% in your browser.
Base64URL Decoder
Decode Base64URL (URL-safe Base64) back to text online. Restores missing = padding, validates the alphabet and decodes JWT segments. Free and 100% private.
Bitwise Calculator
Calculate AND, OR, XOR, NOT and bit shifts on 32-bit values online. Enter operands in any base and see results in decimal, hex, octal and binary at once.
Two's Complement Calculator
Convert signed decimals to two's complement binary and hex — and back — at 8, 16, 32 or 64 bits, with the invert-and-add-one steps shown. Free online tool.
IEEE 754 Floating Point Converter
Convert decimals to IEEE 754 single or double precision and back. See sign, exponent and mantissa bits, the exact stored value and the rounding error.
String Byte Size Calculator
Measure a string's size in UTF-8, UTF-16 and Latin-1 bytes, plus code units and Unicode code points. See why emoji count differently. Free online tool.
Hex Dump Viewer
View any file as a classic hex dump in your browser — offsets, hex bytes and an ASCII column, xxd style. Nothing is uploaded. Copy or download the dump.
Data URI Generator
Turn any file into a base64 data: URI in your browser, with MIME override and ready-to-paste HTML img, CSS url() and favicon snippets. Nothing is uploaded.
Cron Expression Generator
Build a cron expression from simple dropdowns — every N minutes, daily, weekly or monthly — with a plain-English summary. Free and 100% in your browser.
Chmod Calculator
Convert Linux file permissions between rwx checkboxes, octal values like 755 and symbolic strings — with setuid, setgid and sticky bit support. Free tool.
Umask Calculator
See what default file and directory permissions any umask value produces, in octal and symbolic form — or work backwards from the permissions you want.
cURL to Fetch Converter
Paste a curl command and get a ready-to-use JavaScript fetch() snippet plus an axios version — method, headers, body and auth mapped automatically, all offline.
HTTP Header Parser
Paste raw HTTP request or response headers and get a clean name/value table with explanations, directive breakdowns and duplicate detection. Free and private.
Cookie Parser
Decode a Cookie or Set-Cookie header into names, values and attributes — Domain, Path, Expires, SameSite — with security flags for missing attributes.
HTML to JSX Converter
Convert HTML to valid JSX for React: class to className, inline styles to objects, self-closed void tags and camelCased attributes — instantly, in your browser.
Markdown to HTML Converter
Convert Markdown to clean HTML with a live preview — headings, emphasis, links, lists, code blocks, tables and blockquotes. 100% in your browser.
HTML to Markdown Converter
Convert HTML to clean Markdown — headings, emphasis, links, images, nested lists, code blocks, tables and blockquotes — privately in your browser.
.gitignore Generator
Build a .gitignore file by selecting your stack — Node, Python, Java, Go, Rust, Unity, macOS, Windows, IDEs — merged, de-duplicated and ready to download.
Glob Pattern Tester
Test glob patterns like src/**/*.ts against a list of file paths and see matches instantly, with the compiled regex shown. Supports *, **, ?, [abc] and {a,b}.
Semantic Version Checker
Validate semantic versions, compare two versions with correct pre-release precedence, sort a whole list, and see the next major, minor and patch increments.
SVG Minifier
Minify SVG files in your browser: strip comments, metadata and editor junk, round coordinates, collapse whitespace — with a live preview and size savings.
Protobuf Decoder
Decode raw Protocol Buffers wire-format bytes without a .proto file. Paste hex or Base64 and read every field number, wire type and value.
CBOR Decoder
Decode CBOR (RFC 8949) from hex or Base64 into readable JSON and diagnostic notation, with tags, maps, indefinite lengths and half floats.
MessagePack Decoder
Decode MessagePack bytes from hex, Base64 or a dropped file into JSON, with a byte-offset breakdown showing every format byte the encoder used.
ZIP File Viewer
List everything inside a ZIP file without extracting it. See each entry's size, compression method, ratio, CRC-32 and modified date instantly.
File Signature (Magic Number) Identifier
Identify any file's real type from its magic number. Drop a file or paste its first bytes and see whether the extension matches the content.
UUID Decoder
Decode any UUID or GUID. Read its version and variant, and pull the creation timestamp out of version 1, 6 and 7 UUIDs instantly.
Snowflake ID Decoder
Turn a Twitter, X or Discord snowflake ID into a timestamp. Decode the worker, process and sequence bits, or build an ID for a date.
MongoDB ObjectId Decoder
Decode a MongoDB ObjectId into its timestamp, random value and counter, and build a boundary ObjectId for date-range _id queries.
CRC-16 Calculator
Calculate CRC-16 checksums in 12 variants including MODBUS, CCITT-FALSE, XMODEM and KERMIT, from text, hex bytes or a dropped file.
Adler-32 Checksum Calculator
Calculate the Adler-32 checksum used by zlib and PNG from text, hex bytes or a file, with the A and B running sums shown separately.
Endianness Converter
Swap byte order for 16, 32 and 64-bit values. See big-endian and little-endian hex, signed and unsigned decimal, and the float reading.
Base58 Encoder
Encode text or hex bytes to Base58 with the Bitcoin, Ripple or Flickr alphabet, plus optional Base58Check with a version byte and checksum.
Base58 Decoder
Decode Base58 and Base58Check strings to hex, Base64 and text, verify the four-byte checksum and identify the version byte.
Dockerfile Generator
Generate a production-ready Dockerfile and matching .dockerignore for Node, Python, Go, PHP, Java or static sites, with multi-stage builds and a non-root user.
docker run to docker-compose Converter
Convert any docker run command into a docker-compose.yml file. Maps ports, volumes, environment, networks, restart policies and healthchecks to Compose YAML.
GitHub Actions Workflow Generator
Build a .github/workflows CI file from a form: triggers, runner OS, language version matrix, dependency caching, permissions and lint, test and build steps.
EditorConfig Generator
Generate an .editorconfig file with per-language sections for indent style and size, line endings, charset, trailing whitespace and max line length.
Changelog Generator
Turn a list of Conventional Commits into a Keep a Changelog release entry. Groups feat, fix, perf and revert into sections and flags breaking changes.
README Generator
Build a professional README.md from a form: badges, features, install and usage code blocks, options and environment tables, and an auto-generated table of contents.
cURL to Python Requests Converter
Convert any curl command into working Python requests code. Handles headers, JSON and form bodies, basic auth, cookies, query parameters and file uploads.
Postman Collection to cURL Converter
Convert an exported Postman collection into curl commands. Walks nested folders, substitutes {{variables}} and handles raw, form-data and urlencoded bodies.
GraphQL Formatter
Format or minify GraphQL queries, mutations, fragments and SDL schemas. Preserves block strings and comments, and reports the line of any unbalanced brace.
Unified Diff Generator
Compare two texts and generate a real unified diff patch with @@ hunk headers and configurable context, ready to save as .patch and apply with git apply.
CSS Specificity Calculator
Calculate CSS selector specificity as (A,B,C) per Selectors Level 4, including :is(), :not(), :has() and :where(), and rank selectors to see which rule wins.
Unicode Character Inspector
Inspect any text character by character: Unicode code points, UTF-8 bytes, UTF-16 units, HTML entities, CSS and JS escapes, plus NFC, NFD, NFKC and NFKD forms.
OpenAPI to Markdown Converter
Convert an OpenAPI 3.x or Swagger 2.0 JSON spec into readable Markdown API documentation with parameter, request body and response tables.