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.
Compare the execution speed of 2+ JS snippets, run in an isolated Web Worker.
Check if a website is online and see its hosting, WordPress detection, SSL, DNS, SEO and performance.
Test a pattern against text with live match highlighting and capture groups.
Binary arithmetic plus a base converter.
A browser stopwatch with lap times.
Preview a URL at common device viewport sizes.
Convert curl commands to fetch/Python/PHP/HTTPie and back.
Add a duration to a start time and see the resulting date/time.
Carve a VPC CIDR into equal subnets.
Design CSS @keyframes animations.
Generate TypeScript, Go, Java, C# or Python types from sample JSON.
Convert a common YAML subset to JSON and back.
Browse Google's Material Design color palette.
Build an Apple App Store link from an app ID.
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.
Check which web platform features your browser supports.
Show your screen/viewport size live.
Build and send HTTP requests, inspect responses, save history.
Burst-test an endpoint to find its effective rate limit.
Build or decode an HTTP Authorization: Basic header.
Searchable file extension <-> MIME type reference.
Fill in {{variable}} prompt templates and preview the resolved prompt.
Searchable reference of every standard HTTP response status code.
Fetch a URL and explain its response headers, with a security-header grade.
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.
Walk through an OAuth2 Authorization Code flow and inspect tokens.
Compare two API responses and see a structured diff.
Estimate LLM prompt token count.
Convert an OpenAPI/Swagger spec to a Postman Collection and back.
Design REST endpoint specs and generate docs/mocks from them.
Get a unique inbox URL and inspect incoming webhook requests live.
Continuously monitor an endpoint for uptime/latency via cron.
Randomize the order of lines.
Evaluate a math expression with a real parser (no eval) — operators, functions, constants.
Convert between UPPER/lower/Title/camelCase/snake_case/etc.
Reshape a list — trim, dedupe, sort, wrap, and rejoin with any separator.
Convert text into a URL-safe slug.
Searchable reference of regex tokens, quantifiers, and common patterns.
Plain-text line diff with added/removed highlighting.
Find/replace text with regex and whole-word options.
Sort lines alphabetically, A-Z or Z-A.
Normalize an email to its provider-canonical form for deduping.
Search and copy from a curated set of common emoji, grouped by category.
Abbreviate words like "i18n" — first letter, middle count, last letter.
Random common-English filler text.
Convert between Arabic numbers and Roman numerals.
Remove repeated lines, keep the first occurrence.
Spell out text using the NATO phonetic alphabet.
Render text as ASCII art by sampling a real rendered font, not a fixed glyph set.
Parse a phone number into its E.164 calling code, country, and national number.
Subnet math — network/broadcast address, netmask, host range.
Convert data sizes between bytes/KB/MB/GB/TB, decimal or binary.
AND/OR/XOR/NOT/shift with a bit-level view.
Convert between seconds, HH:MM:SS, and human-readable durations.
Decode a MAC address's bit flags plus a best-effort vendor lookup.
Four common percentage calculations in one place.
Generate an RFC 4193 Unique Local Address prefix for private IPv6 numbering.
Convert between Celsius, Fahrenheit, and Kelvin.
Expand a CIDR block or address range into every individual IP address.
Hex arithmetic/bitwise ops plus a base converter.
Convert bps/Mbps/etc. and estimate download time.
Generate random, locally-administered MAC addresses.
Generate random TCP/UDP port numbers for dev servers and configs.
Convert IPv4 to its integer/hex form and IPv4-mapped IPv6.
Follow a web address through every redirect and see status codes, loops and HTTPS upgrades.
Find the holder, origin AS, announced prefix and BGP neighbours for an IP, prefix, AS number or hostname.
Convert a time between zones with daylight saving handled, and find a meeting hour for everyone.
Searchable list of common TCP and UDP ports and the services that use them.
Calculate the TCP window you need and the real throughput given bandwidth, latency and packet loss.
Convert CIDR, subnet and wildcard masks and generate Cisco ACL lines.
Convert MAC address formats, get the IPv6 link-local address and the Wake-on-LAN magic packet.
Summarize IPv4 and IPv6 routes into the smallest list of prefixes or one summary route.
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 8-bit binary bytes.
Convert text to/from hex bytes.
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.
Automatically detect and decode Base64, hex, URL encoding, gzip and more, layer by layer.
Generate secure random tokens/API keys.
Encode or decode Base64 text and files.
Generate sortable, Crockford Base32-encoded ULIDs in bulk.
Generate a live TOTP (RFC 6238) code from a Base32 secret or otpauth:// URI.
Test CORS behavior of an endpoint.
Mask the middle of a string for redacting keys/emails in screenshots.
Hash or verify text with bcrypt, using PHP's native password_hash/password_verify.
Generate MD5/SHA family hashes.
Compute an HMAC from a message and secret key (SHA-1/256/384/512).
Encrypt/decrypt text with common ciphers.
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 a BIP39 mnemonic seed phrase (12-24 words) with correct entropy and checksum.
Find out which algorithm a hash came from, or checksum a file with MD5, SHA-1 and SHA-2.
Check whether a password appears in known data breaches without sending it.
Look up a CVE ID or search by product: severity, CISA KEV status, exploit probability, affected products and references.
Score vulnerabilities with CVSS 3.1: base, temporal and environmental scores and the vector string.
Read the version and creation time inside a UUID, and generate sortable UUID v7 values.
Show the SHA256 and MD5 fingerprint, type and size of an SSH public key and compare it with another.
Build a Content-Security-Policy and find weaknesses in an existing one.
Pull IPs, domains, URLs, emails, hashes and CVEs out of text, and defang or refang links.
Create the integrity attribute and HTML tag for scripts and stylesheets loaded from a CDN.
Decode an X.509 certificate or CSR: subject, issuer, validity, SANs, key and fingerprints.
Create an RFC 9116 security.txt file so researchers know how to report vulnerabilities.
Monitor SSL certificate expiry dates.
Build an AWS IAM policy JSON document.
Build a Terraform variables file.
Toggle Unix file permissions to build a chmod command.
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.
Convert a docker run command into an equivalent docker-compose.yml service block.
Sample event payloads for S3/API Gateway/SNS/SQS/EventBridge.
Convert between plain JSON and DynamoDB AttributeValue JSON.
Build an Apache .htaccess file for redirects, HTTPS, caching, compression and security, with Nginx rules.
Generate a GitHub Actions workflow for Node, Python, PHP, Go, Java, Rust, .NET, Docker or Pages.
Test which versions satisfy an npm-style semantic version range.
Build and explain cron expressions.
Generate a docker-compose.yml.
Generate a Dockerfile for common stacks.
Parse a User-Agent string.
Generate nginx server blocks.
Generate Kubernetes manifests.
Manage and diff .env files.
Monitor site/service uptime.
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.
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.
Build shields.io badges for version, build, licence and downloads and copy them as Markdown or HTML.
Generate a changelog from commit history.
Generate release notes from merged PRs.
Convert between TOML and JSON/YAML.
Pretty-print and validate XML.
Diff two JSON documents.
Validate, pretty-print, and minify JSON.
Validate and format YAML documents.
Convert JSON to XML, mirroring our XML to JSON Converter's conventions.
Generate realistic sample JSON that follows a JSON Schema, with a repeatable seed.
Convert JSON to CSV with flattening, delimiters and Excel-friendly output.
Build a JSON Schema visually from sample data.
Convert between CSV and JSON.
Convert XML documents to JSON.
Validate and preview TOML as JSON.
Test JSONPath expressions against sample JSON.
Convert CSV to a real .xlsx file and back.
Re-indent Firestore security rules.
Convert a Java .properties file to JSON or YAML and back.
Convert between Unix timestamps and dates.
Recover the original URL from a Microsoft Safe Links wrapped link.
Break a URL down into protocol, host, path, query params, and hash.
Build a custom URI scheme deep link.
Build a cross-platform sms: link with a pre-filled message.
Build a Google Play Store link from a package name.
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.
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 to a base64 data URI and back.
Convert an image between formats.
Rasterize SVG markup to PNG or JPEG at any size.
Generate a lightweight inline-SVG placeholder image, no network request.
Turn screenshots into polished images with device frames, gradients, shadows and text.
Turn a code snippet into a styled PNG with themes, window frames and line numbers.
WCAG text/background contrast ratio, AA/AAA pass-fail.
Pick a color, see it in HEX/RGB/HSL.
Convert between RGB and HSV/HSB, the model used by Photoshop/Figma color pickers.
Convert between hex codes and RGB values.
Generate random hex colors (pastel/vibrant/dark).
Convert between RGB and HSL.
Convert between standard CSS named colors and hex codes.
Convert between CMYK (print) and RGB (screen) color values.
Browse Tailwind CSS's default color palette.
Build hreflang alternate-language link tags.
Build a sitemap.xml from a pasted URL list.
Build a robots.txt from rule groups.
Build JSON-LD structured data for common types.
Build a canonical link tag.
Read any website's sitemap, see its page structure as a tree and graph, and check titles, meta tags and status codes.
Build an iOS/macOS Info.plist from common bundle/privacy keys.
Build sample APNs and FCM push payloads.
Validate a google-services.json against the expected Firebase config shape.
Build a .entitlements file (associated domains, app groups, push, iCloud, etc).
Generate all required app icon sizes.
List files/sizes inside an APK.
Generate a mobile app privacy policy.
Analyze keyword competitiveness.
Find high-value ASO keywords.
Manage translation strings across locales.
Generate app store release notes.
Generate App Store/Play Store metadata.
Re-indent or minify CSS.
Convert a CSS length across px, rem, em, pt, and %.
Format minified JavaScript or compact it, with strings, templates and regex handled safely.
Generate all standard favicon sizes.
Design and export CSS gradients.
Design layered CSS box-shadows.
Generate harmonious color palettes.
Visually build Tailwind class combos.
Generate head meta/Open Graph/Twitter Card tags.
Format and minify HTML markup.
Convert between Markdown and HTML.
Minify and clean up SVG markup.
Visually build an HTML table.
Generate glassmorphism CSS.
Generate neumorphism CSS.
Encode or decode HTML entities.
Diff two HTML snapshots.
Convert a font file between TTF/OTF and WOFF.
Generate an EAN-13 barcode.
Format and beautify SQL queries.
Generate an ER diagram from a schema.
Convert CSV rows into INSERT statements.
Visualize table relationships.
Build MongoDB queries visually.
Parse INSERT statements into a JSON array.
Diff two schema/query snapshots.
Analyze a query for potential performance issues.
Visualize an EXPLAIN plan.
Pretty-print a MongoDB query/document.
Search and tail uploaded log files.
Summarize error rates/patterns in logs.
Parse and summarize crash reports.
Annotate screenshots to report bugs.
Pretty-print raw stack traces.
