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.
Convert curl commands to fetch/Python/PHP/HTTPie and back.
Compare the execution speed of 2+ JS snippets, run in an isolated Web Worker.
Check which web platform features your browser supports.
Build a Terraform variables file.
Build and send HTTP requests, inspect responses, save history.
Percent-encode or decode text, component or full-URI mode.
Carve a VPC CIDR into equal subnets.
Binary arithmetic plus a base converter.
Add a duration to a start time and see the resulting date/time.
Turn screenshots into polished images with device frames, gradients, shadows and text.
Generate all required app icon sizes.
Parse and summarize crash reports.
Continuously monitor an endpoint for uptime/latency via cron.
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.
Searchable reference of every standard HTTP response status code.
Searchable file extension <-> MIME type reference.
Burst-test an endpoint to find its effective rate limit.
Build or decode an HTTP Authorization: Basic header.
Fetch a URL and explain its response headers, with a security-header grade.
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.
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.
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 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.
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.
Sort lines alphabetically, A-Z or Z-A.
Convert between UPPER/lower/Title/camelCase/snake_case/etc.
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.
Convert text into a URL-safe slug.
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.
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.
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.
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 MD5/SHA family hashes.
Generate a live TOTP (RFC 6238) code from a Base32 secret or otpauth:// URI.
Generate sortable, Crockford Base32-encoded ULIDs in bulk.
Test CORS behavior of an endpoint.
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.
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.
Decode an X.509 certificate or CSR: subject, issuer, validity, SANs, key and fingerprints.
Score vulnerabilities with CVSS 3.1: base, temporal and environmental scores and the vector string.
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.
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.
Create an RFC 9116 security.txt file so researchers know how to report vulnerabilities.
Monitor SSL certificate expiry dates.
Look up a CVE ID or search by product: severity, CISA KEV status, exploit probability, affected products and references.
Subnet math — network/broadcast address, netmask, host range.
Convert data sizes between bytes/KB/MB/GB/TB, decimal or binary.
Decode a MAC address's bit flags plus a best-effort vendor lookup.
AND/OR/XOR/NOT/shift with a bit-level view.
Four common percentage calculations in one place.
Convert between Celsius, Fahrenheit, and Kelvin.
Convert between seconds, HH:MM:SS, and human-readable durations.
Generate an RFC 4193 Unique Local Address prefix for private IPv6 numbering.
Expand a CIDR block or address range into every individual IP address.
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.
Check if a website is online and see its hosting, WordPress detection, SSL, DNS, SEO and performance.
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.
Follow a web address through every redirect and see status codes, loops and HTTPS upgrades.
Convert a time between zones with daylight saving handled, and find a meeting hour for everyone.
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.
Calculate the TCP window you need and the real throughput given bandwidth, latency and packet loss.
Find the holder, origin AS, announced prefix and BGP neighbours for an IP, prefix, AS number or hostname.
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://).
Convert a .env file to JSON or YAML and back.
Re-indent Terraform configuration.
Look up AWS/GCP/Azure region codes.
Convert between plain JSON and DynamoDB AttributeValue JSON.
Convert a docker run command into an equivalent docker-compose.yml service block.
Sample event payloads for S3/API Gateway/SNS/SQS/EventBridge.
Build and explain cron expressions.
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.
Generate a docker-compose.yml.
Parse a User-Agent string.
Test which versions satisfy an npm-style semantic version range.
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.
Convert between CSV and JSON.
Convert a common YAML subset to JSON and back.
Generate TypeScript, Go, Java, C# or Python types from sample JSON.
Convert JSON to CSV with flattening, delimiters and Excel-friendly output.
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.
Generate realistic sample JSON that follows a JSON Schema, with a repeatable seed.
Resize an image to exact dimensions.
Drag-select and crop an image.
Shrink an image via adjustable JPEG/WebP quality.
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 a code snippet into a styled PNG with themes, window frames and line numbers.
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.
Build shields.io badges for version, build, licence and downloads and copy them as Markdown or HTML.
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.
Recover the original URL from a Microsoft Safe Links wrapped link.
Build a custom URI scheme deep link.
Build a Google Play Store link from a package name.
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.
Convert between standard CSS named colors and hex codes.
Convert between RGB and HSL.
Browse Google's Material Design color palette.
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.
Build a robots.txt from rule groups.
Build a sitemap.xml from a pasted URL list.
Build hreflang alternate-language link tags.
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).
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.
Convert between Markdown and HTML.
Design layered CSS box-shadows.
Generate head meta/Open Graph/Twitter Card tags.
Generate harmonious color palettes.
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.
Annotate screenshots to report bugs.
Summarize error rates/patterns in logs.
Pretty-print raw stack traces.
