API testing, JSON/DB/Git utilities, Cloud generators, AI dev tools and more — free, no signup for the basics.
Press a key to see its KeyboardEvent key/code/keyCode values live.
Convert curl commands to fetch/Python/PHP/HTTPie and back.
Build and send HTTP requests, inspect responses, save history.
Check which web platform features your browser supports.
Searchable reference of every standard HTTP response status code.
Build or decode an HTTP Authorization: Basic header.
Compare the execution speed of 2+ JS snippets, run in an isolated Web Worker.
Build a Terraform variables file.
Percent-encode or decode text, component or full-URI mode.
Carve a VPC CIDR into equal subnets.
Turn screenshots into polished images with device frames, gradients, shadows and text.
A browser stopwatch with lap times.
Show the IP address our server sees you connecting from.
Look up domain registration info.
Generate a scannable QR code.
Generate strong random passwords.
Generate passwords, API keys, AES keys, UUIDs, and RSA/SSH key pairs — all client-side.
Generate v4/v7 UUIDs in bulk.
Classic placeholder text for mockups.
Strip empty/whitespace-only lines.
Live character, word, line, and sentence counts.
Fill in {{variable}} prompt templates and preview the resolved prompt.
Burst-test an endpoint to find its effective rate limit.
Compare two API responses and see a structured diff.
Run queries against any GraphQL endpoint and browse its schema.
Fetch a URL and explain its response headers, with a security-header grade.
Decode and inspect JWT header/payload, verify signatures.
Estimate LLM prompt token count.
Searchable file extension <-> MIME type reference.
Walk through an OAuth2 Authorization Code flow and inspect tokens.
Validate a chat completions request or function/tool schema shape.
Convert an OpenAPI/Swagger spec to a Postman Collection and back.
Design REST endpoint specs and generate docs/mocks from them.
Continuously monitor an endpoint for uptime/latency via cron.
Get a unique inbox URL and inspect incoming webhook requests live.
Preview a URL at common device viewport sizes.
Show your screen/viewport size live.
Manage and diff .env files.
Convert a .env file to JSON or YAML and back.
Parse or build an AWS ARN.
Build an AWS IAM policy JSON document.
Sample event payloads for S3/API Gateway/SNS/SQS/EventBridge.
Parse/build S3 URLs (virtual-hosted, path-style, s3://).
Look up AWS/GCP/Azure region codes.
Toggle Unix file permissions to build a chmod command.
Build and explain cron expressions.
Generate a docker-compose.yml.
Convert a docker run command into an equivalent docker-compose.yml service block.
Generate a Dockerfile for common stacks.
Convert between plain JSON and DynamoDB AttributeValue JSON.
Generate Kubernetes manifests.
Generate nginx server blocks.
Re-indent Terraform configuration.
Parse a User-Agent string.
Monitor site/service uptime.
Convert between CMYK (print) and RGB (screen) color values.
Convert between standard CSS named colors and hex codes.
Pick a color, see it in HEX/RGB/HSL.
Convert between hex codes and RGB values.
Browse Google's Material Design color palette.
Generate random hex colors (pastel/vibrant/dark).
Convert between RGB and HSL.
Convert between RGB and HSV/HSB, the model used by Photoshop/Figma color pickers.
Browse Tailwind CSS's default color palette.
WCAG text/background contrast ratio, AA/AAA pass-fail.
Generate harmonious color palettes.
Design CSS @keyframes animations.
Design layered CSS box-shadows.
Re-indent or minify CSS.
Design and export CSS gradients.
Generate all standard favicon sizes.
Convert a font file between TTF/OTF and WOFF.
Generate glassmorphism CSS.
Diff two HTML snapshots.
Encode or decode HTML entities.
Format and minify HTML markup.
Visually build an HTML table.
Convert between Markdown and HTML.
Generate head meta/Open Graph/Twitter Card tags.
Generate neumorphism CSS.
Convert a CSS length across px, rem, em, pt, and %.
Minify and clean up SVG markup.
Visually build Tailwind class combos.
Convert CSV rows into INSERT statements.
Visualize table relationships.
Generate an ER diagram from a schema.
Build MongoDB queries visually.
Pretty-print a MongoDB query/document.
Visualize an EXPLAIN plan.
Diff two schema/query snapshots.
Format and beautify SQL queries.
Analyze a query for potential performance issues.
Parse INSERT statements into a JSON array.
Convert text to/from Base32 (RFC 4648).
Convert text to/from Base58 (Bitcoin alphabet).
Convert Base64 to a hex byte string and back.
Convert any file to a Base64 data URI, entirely in your browser.
Convert a URL query string to a JSON object and back.
Convert text to/from decimal character codes.
Convert text to/from 8-bit binary bytes.
Convert text to/from hex bytes.
Convert text to/from Unicode code points (U+XXXX).
Generate fake street addresses for testing.
Generate fake phone numbers (US 555 exchange, etc).
Generate fake names/emails/usernames for testing.
Generate Luhn-valid dummy card numbers for sandbox testing.
Generate test email addresses on RFC 2606 reserved domains.
Build a .gitignore from checklists by language, editor, and OS.
Generate a changelog from commit history.
Find stale/merged branches to clean up.
Searchable reference of common git commands.
Generate a conventional-commit message.
Visualize and help resolve merge conflicts.
Generate release notes from merged PRs.
Shrink an image via adjustable JPEG/WebP quality.
Drag-select and crop an image.
Convert an image between formats.
Resize an image to exact dimensions.
Convert an image to a base64 data URI and back.
Generate a lightweight inline-SVG placeholder image, no network request.
Rasterize SVG markup to PNG or JPEG at any size.
Preview SVG markup safely (rendered as an image, not injected).
Convert CSV to a real .xlsx file and back.
Convert between CSV and JSON.
Re-indent Firestore security rules.
Diff two JSON documents.
Validate, pretty-print, and minify JSON.
Build a JSON Schema visually from sample data.
Convert JSON to XML, mirroring our XML to JSON Converter's conventions.
Test JSONPath expressions against sample JSON.
Convert a Java .properties file to JSON or YAML and back.
Validate and preview TOML as JSON.
Convert between TOML and JSON/YAML.
Pretty-print and validate XML.
Convert XML documents to JSON.
Convert a common YAML subset to JSON and back.
Validate and format YAML documents.
Parse and summarize crash reports.
Summarize error rates/patterns in logs.
Search and tail uploaded log files.
Annotate screenshots to report bugs.
Pretty-print raw stack traces.
List files/sizes inside an APK.
Generate all required app icon sizes.
Manage translation strings across locales.
Generate a mobile app privacy policy.
Generate app store release notes.
Analyze keyword competitiveness.
Generate App Store/Play Store metadata.
Find high-value ASO keywords.
Validate a google-services.json against the expected Firebase config shape.
Build an iOS/macOS Info.plist from common bundle/privacy keys.
Build a .entitlements file (associated domains, app groups, push, iCloud, etc).
Build sample APNs and FCM push payloads.
Add a duration to a start time and see the resulting date/time.
Binary arithmetic plus a base converter.
AND/OR/XOR/NOT/shift with a bit-level view.
Subnet math — network/broadcast address, netmask, host range.
Convert data sizes between bytes/KB/MB/GB/TB, decimal or binary.
Convert bps/Mbps/etc. and estimate download time.
Hex arithmetic/bitwise ops plus a base converter.
Convert IPv4 to its integer/hex form and IPv4-mapped IPv6.
Expand a CIDR block or address range into every individual IP address.
Generate an RFC 4193 Unique Local Address prefix for private IPv6 numbering.
Decode a MAC address's bit flags plus a best-effort vendor lookup.
Four common percentage calculations in one place.
Generate random, locally-administered MAC addresses.
Generate random TCP/UDP port numbers for dev servers and configs.
Convert between Celsius, Fahrenheit, and Kelvin.
Convert between seconds, HH:MM:SS, and human-readable durations.
Check if a website is online and see its hosting, WordPress detection, SSL, DNS, SEO and performance.
Generate an EAN-13 barcode.
Encrypt/decrypt text with common ciphers.
Encode or decode Base64 text and files.
Hash or verify text with bcrypt, using PHP's native password_hash/password_verify.
Generate a BIP39 mnemonic seed phrase (12-24 words) with correct entropy and checksum.
Test CORS behavior of an endpoint.
Generate MD5/SHA family hashes.
Compute an HMAC from a message and secret key (SHA-1/256/384/512).
Validate an IBAN's mod-97 checksum and break it into country/BBAN.
Score a password's strength and estimate crack time, entirely client-side.
Generate secure random tokens/API keys.
Monitor SSL certificate expiry dates.
Mask the middle of a string for redacting keys/emails in screenshots.
Generate a live TOTP (RFC 6238) code from a Base32 secret or otpauth:// URI.
Generate sortable, Crockford Base32-encoded ULIDs in bulk.
Build a canonical link tag.
Build hreflang alternate-language link tags.
Build a robots.txt from rule groups.
Build JSON-LD structured data for common types.
Build a sitemap.xml from a pasted URL list.
Render text as ASCII art by sampling a real rendered font, not a fixed glyph set.
Reshape a list — trim, dedupe, sort, wrap, and rejoin with any separator.
Normalize an email to its provider-canonical form for deduping.
Search and copy from a curated set of common emoji, grouped by category.
Find/replace text with regex and whole-word options.
Spell out text using the NATO phonetic alphabet.
Abbreviate words like "i18n" — first letter, middle count, last letter.
Evaluate a math expression with a real parser (no eval) — operators, functions, constants.
Parse a phone number into its E.164 calling code, country, and national number.
Randomize the order of lines.
Random common-English filler text.
Searchable reference of regex tokens, quantifiers, and common patterns.
Test a pattern against text with live match highlighting and capture groups.
Remove repeated lines, keep the first occurrence.
Convert between Arabic numbers and Roman numerals.
Sort lines alphabetically, A-Z or Z-A.
Convert between UPPER/lower/Title/camelCase/snake_case/etc.
Plain-text line diff with added/removed highlighting.
Convert text into a URL-safe slug.
Build an Apple App Store link from an app ID.
Build a custom URI scheme deep link.
Build a Google Play Store link from a package name.
Build a mailto: link with subject/body/cc/bcc.
Recover the original URL from a Microsoft Safe Links wrapped link.
Build a cross-platform sms: link with a pre-filled message.
Convert between Unix timestamps and dates.
Follow redirects to the final destination.
Break a URL down into protocol, host, path, query params, and hash.
Create short redirect links.
Build a wa.me click-to-chat link.
