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.
Convert curl commands to fetch/Python/PHP/HTTPie and back.
Binary arithmetic plus a base converter.
Check which web platform features your browser supports.
Percent-encode or decode text, component or full-URI mode.
Add a duration to a start time and see the resulting date/time.
Build a Terraform variables file.
Build and send HTTP requests, inspect responses, save history.
Walk through an OAuth2 Authorization Code flow and inspect tokens.
Estimate LLM prompt token count.
Manage translation strings across locales.
Visually build an HTML table.
Convert between Markdown and HTML.
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.
Burst-test an endpoint to find its effective rate limit.
Searchable file extension <-> MIME type reference.
Build or decode an HTTP Authorization: Basic header.
Searchable reference of every standard HTTP response status code.
Fill in {{variable}} prompt templates and preview the resolved prompt.
Validate a chat completions request or function/tool schema shape.
Fetch a URL and explain its response headers, with a security-header grade.
Decode and inspect JWT header/payload, verify signatures.
Get a unique inbox URL and inspect incoming webhook requests live.
Convert an OpenAPI/Swagger spec to a Postman Collection and back.
Run queries against any GraphQL endpoint and browse its schema.
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.
Subnet math — network/broadcast address, netmask, host range.
Convert data sizes between bytes/KB/MB/GB/TB, decimal or binary.
Expand a CIDR block or address range into every individual IP address.
AND/OR/XOR/NOT/shift with a bit-level view.
Generate an RFC 4193 Unique Local Address prefix for private IPv6 numbering.
Four common percentage calculations in one place.
Convert between Celsius, Fahrenheit, and Kelvin.
Convert between seconds, HH:MM:SS, and human-readable durations.
Decode a MAC address's bit flags plus a best-effort vendor lookup.
Hex arithmetic/bitwise ops plus a base converter.
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.
Searchable list of common TCP and UDP ports and the services that use them.
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.
Follow a web address through every redirect and see status codes, loops and HTTPS upgrades.
Convert CIDR, subnet and wildcard masks and generate Cisco ACL lines.
Calculate the TCP window you need and the real throughput given bandwidth, latency and packet loss.
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.
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.
Searchable reference of regex tokens, quantifiers, and common patterns.
Find/replace text with regex and whole-word options.
Randomize the order of lines.
Sort lines alphabetically, A-Z or Z-A.
Plain-text line diff with added/removed highlighting.
Reshape a list — trim, dedupe, sort, wrap, and rejoin with any separator.
Search and copy from a curated set of common emoji, grouped by category.
Normalize an email to its provider-canonical form for deduping.
Convert text into a URL-safe slug.
Random common-English filler text.
Abbreviate words like "i18n" — first letter, middle count, last letter.
Convert between Arabic numbers and Roman numerals.
Spell out text using the NATO phonetic alphabet.
Remove repeated lines, keep the first occurrence.
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.
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.
Generate secure random tokens/API keys.
Encode or decode Base64 text and files.
Generate a live TOTP (RFC 6238) code from a Base32 secret or otpauth:// URI.
Hash or verify text with bcrypt, using PHP's native password_hash/password_verify.
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).
Generate sortable, Crockford Base32-encoded ULIDs in bulk.
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.
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.
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.
Score vulnerabilities with CVSS 3.1: base, temporal and environmental scores and the vector string.
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.
Decode an X.509 certificate or CSR: subject, issuer, validity, SANs, key and fingerprints.
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.
Monitor SSL certificate expiry dates.
Build an AWS IAM policy JSON document.
Parse or build an AWS ARN.
Carve a VPC CIDR into equal subnets.
Toggle Unix file permissions to build a chmod command.
Parse/build S3 URLs (virtual-hosted, path-style, s3://).
Re-indent Terraform configuration.
Sample event payloads for S3/API Gateway/SNS/SQS/EventBridge.
Look up AWS/GCP/Azure region codes.
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.
Generate a GitHub Actions workflow for Node, Python, PHP, Go, Java, Rust, .NET, Docker or Pages.
Build an Apache .htaccess file for redirects, HTTPS, caching, compression and security, with Nginx rules.
Test which versions satisfy an npm-style semantic version range.
Generate a docker-compose.yml.
Build and explain cron expressions.
Parse a User-Agent string.
Generate a Dockerfile for common stacks.
Generate nginx server blocks.
Generate Kubernetes manifests.
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.
Convert JSON to CSV with flattening, delimiters and Excel-friendly output.
Generate realistic sample JSON that follows a JSON Schema, with a repeatable seed.
Generate TypeScript, Go, Java, C# or Python types from sample JSON.
Convert between CSV and JSON.
Convert a common YAML subset to JSON and back.
Build a JSON Schema visually from sample data.
Convert XML documents to JSON.
Test JSONPath expressions against sample JSON.
Re-indent Firestore security rules.
Validate and preview TOML as JSON.
Convert CSV to a real .xlsx file and back.
Convert a Java .properties file to JSON or YAML and back.
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.
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.
Browse Tailwind CSS's default color palette.
Convert between CMYK (print) and RGB (screen) color values.
Browse Google's Material Design color palette.
Generate test email addresses on RFC 2606 reserved domains.
Generate fake names/emails/usernames for testing.
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.
Recover the original URL from a Microsoft Safe Links wrapped link.
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.
Build a wa.me click-to-chat link.
Build a mailto: link with subject/body/cc/bcc.
Build an Apple App Store link from an app ID.
Create short redirect links.
Follow redirects to the final destination.
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.
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.
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.
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 App Store/Play Store metadata.
Analyze keyword competitiveness.
Find high-value ASO keywords.
Generate app store release notes.
Generate a mobile app privacy policy.
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.
Design and export CSS gradients.
Design layered CSS box-shadows.
Generate head meta/Open Graph/Twitter Card tags.
Format and minify HTML markup.
Generate harmonious color palettes.
Minify and clean up SVG markup.
Generate all standard favicon sizes.
Encode or decode HTML entities.
Design CSS @keyframes animations.
Generate glassmorphism CSS.
Generate neumorphism CSS.
Visually build Tailwind class combos.
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.
Parse INSERT statements into a JSON array.
Build MongoDB queries visually.
Convert CSV rows into INSERT statements.
Diff two schema/query snapshots.
Analyze a query for potential performance issues.
Visualize table relationships.
Visualize an EXPLAIN plan.
Pretty-print a MongoDB query/document.
Search and tail uploaded log files.
Summarize error rates/patterns in logs.
Annotate screenshots to report bugs.
Pretty-print raw stack traces.
Parse and summarize crash reports.
