Developer Tools
43A request bin that receives webhooks live, an HTTP request tester with redirect chains and timing, a WebSocket client, a cron builder and explainer, HTTP status and MIME type references, URL and User-Agent parsers, code formatters and minifiers.
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Request Bin
Get a unique URL that captures every webhook or HTTP request and shows it live — headers, body, query, raw wire format.
HTTP Request Tester
Send GET, POST, PUT and other requests to any public URL and inspect status, headers, body, redirects and timing.
Regex Tester
Test regular expressions with in-place highlighting, a token-by-token explainer and code export.
Cron Expression Parser
Parse, build and explain cron expressions with next/previous runs, timezones and YAML export.
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JSON Formatter
Beautify, minify, sort, query and repair JSON with a tree view and copy-as code export.
JSON Validator
Validate JSON syntax and JSON Schema, catch duplicate keys and precision loss, check NDJSON line by line.
JSON Minifier
Minify JSON, strip nulls, measure gzip size and encode as Base64 or URL-safe text.
JSON Diff
Compare two JSON documents side by side, ignore keys, match arrays by id and export JSON Patch or Merge Patch.
JSON Path Finder
Explore JSON as a tree, click any value to copy its path in 7 syntaxes, and evaluate JSONPath or jq queries.
Base64 Encode / Decode
Encode text, hex or any file to Base64 (and Base32, Base58) and decode back — with data URIs and image preview.
URL Encode / Decode
Percent-encode text with encodeURIComponent, encodeURI, form or RFC 3986 rules, decode multi-layer strings, and edit query strings in a table.
JWT Decoder
Decode, verify (HS/RS/ES/PS, JWKS) and sign JWTs
JWT Debugger
Verify and sign JWTs with a secret, public key or JWKS.
UUID Generator & Inspector
Generate UUID v1/v3/v4/v5/v6/v7, ULIDs and nanoids in bulk, inspect any UUID, and validate lists.
Hash Generator
MD5, SHA-1, SHA-256/384/512, SHA-3, CRC32 and xxHash32 for text, lines and files — with verify and checksum export.
HMAC Generator & Verifier
Sign and verify HMAC-SHA256/SHA1/SHA512/MD5/SHA-3 signatures with Stripe, GitHub, Shopify, Slack and Twilio presets.
QR Code Generator
QR codes for URLs, Wi-Fi, vCards, SMS, email, geo, events, WhatsApp, 2FA and crypto — with logo, styles and print-ready export.
Random Number Generator
Random integers and decimals, normal/exponential/weighted distributions, dice rolls, coin flips, and list shuffles or raffle picks.
Case Converter
Convert text between camelCase, snake_case, kebab-case, Title Case and 15 more — per line or as a whole.
Slug Generator
Turn titles into clean URL slugs with transliteration for Cyrillic, Greek, Arabic and more, stop-word removal, templates and uniqueness.
Text Diff
Compare two texts side-by-side with word-level highlights and export a unified patch.
Markdown Preview
Live split-pane Markdown editor with highlighted code blocks, TOC and styled HTML export.
String Escape / Unescape
Escape or unescape strings for JSON, JS, HTML, XML, URL, regex, shell, CSV, SQL, Python, Java, C#, Go, YAML and .properties.
CSS Minifier
Minify CSS safely — strings, url() and calc() preserved — with gzip size and duplicate-selector merging.
JavaScript Minifier
Minify JavaScript with Terser or beautify JS/TS with Prettier — with real gzip sizes.
SQL Formatter
Format, minify and highlight SQL for 14 dialects with placeholder substitution.
HTML / CSS Prettifier
Beautify or minify HTML, CSS, SCSS, Less, JS, TS, JSON, YAML, Markdown and more — with preview and lint.
HTTP Status Codes
Searchable reference for every HTTP status code.
Number Base Converter
Convert between binary, octal, decimal, hex and any base 2–36, with a bit grid, bitwise ops and IEEE-754.
Unix Timestamp Converter
Convert Unix timestamps (s, ms, µs, ns) to dates and back, across time zones, with custom formats and code.
URL Parser & Query Editor
Break any URL into parts, edit query params live, unwrap nested redirect URLs, decode ad macros, build UTMs and follow redirects.
User-Agent Parser
Parse any User-Agent — browsers, in-app webviews, CTV (Roku, Tizen, webOS, Fire TV), bots — merge Client Hints and get an OpenRTB device object.
SVG Optimizer
Optimize SVGs with SVGO and export as React, Vue, Svelte, data URI, sprite or PNG.
Percentage Calculator
Nine percentage modes: of, what %, of what, change, add/subtract, reverse, points, CAGR and fractions.
Date Difference Calculator
Days between dates, business days with holidays, date ± N, age and live countdowns.
Byte / Data Size Converter
Convert data sizes between SI and binary units side by side, and calculate transfer times.
Aspect Ratio Calculator
Solve dimensions for any ratio, fit or crop into a box, and get resolution tables and CSS snippets.
Text to Binary
Convert text or files to binary, hex, octal or decimal bytes and back, with a hex dump, per-character byte table and five encodings.
IP Address Lookup & Subnet Calculator
Look up any IP: RDAP owner and ASN allocation, reverse DNS, what’s-my-IP, IPv4/IPv6 subnet math, bulk classification.
chmod Calculator
Convert between numeric and symbolic Unix permissions, with umask, warnings and recipes.
HLS m3u8 Parser
Fetch or paste HLS playlists — drill from master to variants, validate the ladder, HEAD-check segments, decode SCTE-35 cues.
WebSocket Tester
Connect to any ws:// or wss:// endpoint, send text/JSON/binary frames, measure RTT, and debug Socket.IO, STOMP, graphql-ws and MQTT handshakes.
MIME Type Lookup
Find the right Content-Type for any extension, check what a URL actually serves, and identify files by magic bytes.