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.
Convert curl commands to fetch/Python/PHP/HTTPie and back.
Check which web platform features your browser supports.
Percent-encode or decode text, component or full-URI mode.
Build a Terraform variables file.
Add a duration to a start time and see the resulting date/time.
Build and send HTTP requests, inspect responses, save history.
Burst-test an endpoint to find its effective rate limit.
Carve a VPC CIDR into equal subnets.
Build an Apache .htaccess file for redirects, HTTPS, caching, compression and security, with Nginx rules.
Convert between CSV and JSON.
Build an Apple App Store link from an app ID.
Generate a docker-compose.yml.
Generate harmonious color palettes.
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.
Searchable file extension <-> MIME type reference.
Searchable reference of every standard HTTP response status code.
Build or decode an HTTP Authorization: Basic header.
Fill in {{variable}} prompt templates and preview the resolved prompt.
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.
Get a unique inbox URL and inspect incoming webhook requests live.
Convert an OpenAPI/Swagger spec to a Postman Collection and back.
Walk through an OAuth2 Authorization Code flow and inspect tokens.
Estimate LLM prompt token count.
Design REST endpoint specs and generate docs/mocks from them.
Continuously monitor an endpoint for uptime/latency via cron.
Compare two API responses and see a structured diff.
Preview a URL at common device viewport sizes.
Show your screen/viewport size live.
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 Base32 (RFC 4648).
Convert text to/from hex bytes.
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.
Binary arithmetic plus a base converter.
Convert data sizes between bytes/KB/MB/GB/TB, decimal or binary.
Subnet math — network/broadcast address, netmask, host range.
Convert between Celsius, Fahrenheit, and Kelvin.
AND/OR/XOR/NOT/shift with a bit-level view.
Decode a MAC address's bit flags plus a best-effort vendor lookup.
Expand a CIDR block or address range into every individual IP address.
Convert between seconds, HH:MM:SS, and human-readable durations.
Four common percentage calculations in one place.
Generate an RFC 4193 Unique Local Address prefix for private IPv6 numbering.
Hex arithmetic/bitwise ops plus a base converter.
Check if a website is online and see its hosting, WordPress detection, SSL, DNS, SEO and performance.
Generate random TCP/UDP port numbers for dev servers and configs.
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.
Follow a web address through every redirect and see status codes, loops and HTTPS upgrades.
Searchable list of common TCP and UDP ports and the services that use them.
Convert a time between zones with daylight saving handled, and find a meeting hour for everyone.
Find the holder, origin AS, announced prefix and BGP neighbours for an IP, prefix, AS number or hostname.
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.
Calculate the TCP window you need and the real throughput given bandwidth, latency and packet loss.
Summarize IPv4 and IPv6 routes into the smallest list of prefixes or one summary route.
Test a pattern against text with live match highlighting and capture groups.
Evaluate a math expression with a real parser (no eval) — operators, functions, constants.
Convert between UPPER/lower/Title/camelCase/snake_case/etc.
Sort lines alphabetically, A-Z or Z-A.
Randomize the order of lines.
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.
Reshape a list — trim, dedupe, sort, wrap, and rejoin with any separator.
Convert text into a URL-safe slug.
Search and copy from a curated set of common emoji, grouped by category.
Random common-English filler text.
Abbreviate words like "i18n" — first letter, middle count, last letter.
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.
Generate secure random tokens/API keys.
Encode or decode Base64 text and files.
Compute an HMAC from a message and secret key (SHA-1/256/384/512).
Generate MD5/SHA family hashes.
Generate a live TOTP (RFC 6238) code from a Base32 secret or otpauth:// URI.
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.
Mask the middle of a string for redacting keys/emails in screenshots.
Encrypt/decrypt text with common ciphers.
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.
Look up a CVE ID or search by product: severity, CISA KEV status, exploit probability, affected products and references.
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.
Read the version and creation time inside a UUID, and generate sortable UUID v7 values.
Score vulnerabilities with CVSS 3.1: base, temporal and environmental scores and the vector string.
Decode an X.509 certificate or CSR: subject, issuer, validity, SANs, key and fingerprints.
Show the SHA256 and MD5 fingerprint, type and size of an SSH public key and compare it with another.
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.
Create an RFC 9116 security.txt file so researchers know how to report vulnerabilities.
Build a Content-Security-Policy and find weaknesses in an existing one.
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.
Re-indent Terraform configuration.
Convert a .env file to JSON or YAML and back.
Convert a docker run command into an equivalent docker-compose.yml service block.
Convert between plain JSON and DynamoDB AttributeValue JSON.
Sample event payloads for S3/API Gateway/SNS/SQS/EventBridge.
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.
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.
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.
Generate realistic sample JSON that follows a JSON Schema, with a repeatable seed.
Convert JSON to CSV with flattening, delimiters and Excel-friendly output.
Generate TypeScript, Go, Java, C# or Python types from sample 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.
Shrink an image via adjustable JPEG/WebP quality.
Drag-select and crop an image.
Resize an image to exact dimensions.
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.
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.
Convert between Unix timestamps and dates.
Break a URL down into protocol, host, path, query params, and hash.
Recover the original URL from a Microsoft Safe Links wrapped link.
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 mailto: link with subject/body/cc/bcc.
Build a wa.me click-to-chat link.
Create short redirect links.
Follow redirects to the final destination.
Build a .gitignore from checklists by language, editor, and OS.
Visualize and help resolve merge conflicts.
Searchable reference of common git commands.
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.
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.
WCAG text/background contrast ratio, AA/AAA pass-fail.
Pick a color, see it in HEX/RGB/HSL.
Generate random hex colors (pastel/vibrant/dark).
Convert between hex codes and RGB values.
Convert between RGB and HSL.
Convert between standard CSS named colors and hex codes.
Convert between RGB and HSV/HSB, the model used by Photoshop/Figma color pickers.
Convert between CMYK (print) and RGB (screen) color values.
Browse Tailwind CSS's default color palette.
Browse Google's Material Design color palette.
Build a sitemap.xml from a pasted URL list.
Build hreflang alternate-language link tags.
Build a robots.txt from rule groups.
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.
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 App Store/Play Store metadata.
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 minified JavaScript or compact it, with strings, templates and regex handled safely.
Format and minify HTML markup.
Design and export CSS gradients.
Convert between Markdown and HTML.
Design layered CSS box-shadows.
Generate head meta/Open Graph/Twitter Card tags.
Generate all standard favicon sizes.
Minify and clean up SVG markup.
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.
Parse and summarize crash reports.
Annotate screenshots to report bugs.
Summarize error rates/patterns in logs.
Pretty-print raw stack traces.
