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.
Build an iOS/macOS Info.plist from common bundle/privacy keys.
Preview a URL at common device viewport sizes.
Add a duration to a start time and see the resulting date/time.
Convert curl commands to fetch/Python/PHP/HTTPie and back.
Test a pattern against text with live match highlighting and capture groups.
Percent-encode or decode text, component or full-URI mode.
Convert text to/from 8-bit binary bytes.
Test JSONPath expressions against sample JSON.
Design CSS @keyframes animations.
Generate realistic sample JSON that follows a JSON Schema, with a repeatable seed.
Decode and inspect JWT header/payload, verify signatures.
Build a JSON Schema visually from sample data.
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.
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.
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.
Walk through an OAuth2 Authorization Code flow and inspect tokens.
Design REST endpoint specs and generate docs/mocks from them.
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.
Run queries against any GraphQL endpoint and browse its schema.
Get a unique inbox URL and inspect incoming webhook requests live.
Continuously monitor an endpoint for uptime/latency via cron.
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 Base32 (RFC 4648).
Convert text to/from Base58 (Bitcoin alphabet).
Convert any file to a Base64 data URI, entirely in your browser.
Convert a URL query string to a JSON object and back.
Convert Base64 to a hex byte string and back.
Automatically detect and decode Base64, hex, URL encoding, gzip and more, layer by layer.
Binary arithmetic plus a base converter.
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.
Expand a CIDR block or address range into every individual IP address.
Generate an RFC 4193 Unique Local Address prefix for private IPv6 numbering.
Convert between Celsius, Fahrenheit, and Kelvin.
Hex arithmetic/bitwise ops plus a base converter.
Generate random, locally-administered MAC addresses.
Convert IPv4 to its integer/hex form and IPv4-mapped IPv6.
Convert bps/Mbps/etc. and estimate download time.
Generate random TCP/UDP port numbers for dev servers and configs.
Find the holder, origin AS, announced prefix and BGP neighbours for an IP, prefix, AS number or hostname.
Follow a web address through every redirect and see status codes, loops and HTTPS upgrades.
Calculate the TCP window you need and the real throughput given bandwidth, latency and packet loss.
Convert a time between zones with daylight saving handled, and find a meeting hour for everyone.
Convert MAC address formats, get the IPv6 link-local address and the Wake-on-LAN magic packet.
Convert CIDR, subnet and wildcard masks and generate Cisco ACL lines.
Searchable list of common TCP and UDP ports and the services that use them.
Summarize IPv4 and IPv6 routes into the smallest list of prefixes or one summary route.
Evaluate a math expression with a real parser (no eval) — operators, functions, constants.
Randomize the order of lines.
Find/replace text with regex and whole-word options.
Convert between UPPER/lower/Title/camelCase/snake_case/etc.
Plain-text line diff with added/removed highlighting.
Searchable reference of regex tokens, quantifiers, and common patterns.
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.
Convert text into a URL-safe slug.
Sort lines alphabetically, A-Z or Z-A.
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.
Render text as ASCII art by sampling a real rendered font, not a fixed glyph set.
Spell out text using the NATO phonetic alphabet.
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.
Generate sortable, Crockford Base32-encoded ULIDs in bulk.
Generate MD5/SHA family hashes.
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.
Compute an HMAC from a message and secret key (SHA-1/256/384/512).
Mask the middle of a string for redacting keys/emails in screenshots.
Encrypt/decrypt text with common ciphers.
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.
Score a password's strength and estimate crack time, entirely client-side.
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.
Find out which algorithm a hash came from, or checksum a file with MD5, SHA-1 and SHA-2.
Build a Content-Security-Policy and find weaknesses in an existing one.
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.
Show the SHA256 and MD5 fingerprint, type and size of an SSH public key and compare it with another.
Create the integrity attribute and HTML tag for scripts and stylesheets loaded from a CDN.
Pull IPs, domains, URLs, emails, hashes and CVEs out of text, and defang or refang links.
Create an RFC 9116 security.txt file so researchers know how to report vulnerabilities.
Decode an X.509 certificate or CSR: subject, issuer, validity, SANs, key and fingerprints.
Monitor SSL certificate expiry dates.
Build an AWS IAM policy JSON document.
Carve a VPC CIDR into equal subnets.
Toggle Unix file permissions to build a chmod command.
Build a Terraform variables file.
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.
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.
Manage and diff .env files.
Generate a Dockerfile for common stacks.
Generate a docker-compose.yml.
Build and explain cron expressions.
Parse a User-Agent string.
Generate nginx server blocks.
Generate Kubernetes manifests.
Monitor site/service uptime.
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.
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 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 TypeScript, Go, Java, C# or Python types from sample JSON.
Validate and preview TOML as JSON.
Convert XML documents to JSON.
Convert between CSV and JSON.
Convert a common YAML subset to JSON and back.
Convert a Java .properties file to JSON or YAML and back.
Re-indent Firestore security rules.
Convert CSV to a real .xlsx file and back.
Drag-select and crop an image.
Shrink an image via adjustable JPEG/WebP quality.
Resize an image to exact dimensions.
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.
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 an Apple App Store link from an app ID.
Build a mailto: link with subject/body/cc/bcc.
Build a wa.me click-to-chat link.
Follow redirects to the final destination.
Create short redirect links.
WCAG text/background contrast ratio, AA/AAA pass-fail.
Pick a color, see it in HEX/RGB/HSL.
Convert between hex codes and RGB values.
Convert between RGB and HSV/HSB, the model used by Photoshop/Figma color pickers.
Convert between RGB and HSL.
Generate random hex colors (pastel/vibrant/dark).
Convert between CMYK (print) and RGB (screen) color values.
Browse Tailwind CSS's default color palette.
Browse Google's Material Design color palette.
Convert between standard CSS named colors and hex codes.
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 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.
Analyze keyword competitiveness.
Generate a mobile app privacy policy.
Find high-value ASO keywords.
Manage translation strings across locales.
List files/sizes inside an APK.
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.
Generate harmonious color palettes.
Minify and clean up SVG markup.
Design layered CSS box-shadows.
Visually build an HTML table.
Generate glassmorphism CSS.
Design and export CSS gradients.
Encode or decode HTML entities.
Generate head meta/Open Graph/Twitter Card tags.
Convert between Markdown and HTML.
Generate neumorphism CSS.
Diff two HTML snapshots.
Convert a font file between TTF/OTF and WOFF.
Visually build Tailwind class combos.
Format and minify HTML markup.
Generate an EAN-13 barcode.
Convert CSV rows into INSERT statements.
Format and beautify SQL queries.
Build MongoDB queries visually.
Parse INSERT statements into a JSON array.
Visualize table relationships.
Analyze a query for potential performance issues.
Generate an ER diagram from a schema.
Pretty-print a MongoDB query/document.
Diff two schema/query snapshots.
Visualize an EXPLAIN plan.
Summarize error rates/patterns in logs.
Search and tail uploaded log files.
Pretty-print raw stack traces.
Annotate screenshots to report bugs.
Parse and summarize crash reports.
