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