Beautiful tools for developers

Paste a git diff, get a conventional commit message from an LLM — bring your own free Groq key, called straight from your browser.

Assemble a system prompt from ordered blocks — role, context, constraints, output format — with a live token count, soft-limit warnings, and a shareable URL. 100% client-side.

Turn a text prompt into a 1024×1024 image with FLUX.1 [schnell] on Cloudflare Workers AI. No account, no API key — rate-limited for fair use. Your prompt goes to the model through our Worker; we store no prompts and no images.

Find what your prompts share — common prefix and suffix blocks — and place prompt-cache breakpoints where they pay, with an estimated cost saving. 100% client-side.

See what prompt caching saves — uncached vs cached cost over N requests, with the write-premium break-even point.

Convert chat transcripts between OpenAI messages[], Anthropic system+messages, Gemini contents[], and plain Markdown. Roles map faithfully, tool calls are preserved where possible, and anything unmappable is flagged — never dropped silently. Runs entirely in your browser.

Paste your system prompt, docs, and history — see how they fill any model's context window, with overflow warnings and output headroom.

Plan how to fit a long chat history into a context budget — which turns to keep, fold into a summary, or drop, protecting system messages and the current request. 100% client-side.

Plan document chunking for RAG — chunk counts with overlap math, vector counts, and embedding costs per model.

The standard LLM-eval numbers with exact math — unbiased pass@k, precision/recall/F1 from confusion counts, exact-match and label-set micro-F1. 100% client-side.

Estimate the vision token cost of an image before sending it to an LLM - low/high/auto detail modes, the 512px tile math, the 2048/768 downscaling steps, and a full base + tiles + detail breakdown. Runs entirely in your browser.

Fix broken JSON - trailing commas, single quotes, unquoted keys, comments, Python constants, BOM and truncated documents - and get clean pretty-printed JSON plus a list of every repair applied. Runs entirely in your browser.

Estimate LLM costs per request or per month at billion-token scale — with realistic prompt-cache hit rates, four-lane pricing, and side-by-side model comparison from a dated pricing snapshot.

Generate deterministic mock LLM API responses - chat completion JSON, SSE event streams with chunk timing, and a replay curl - for testing clients without an API key.

Filter every major model by context window, price, modality, and tier — sort by cost, context, or tokens-per-dollar to find the right model for the task.

Chunk one document three ways — fixed-size, sentence-aware, markdown-heading-aware — and compare counts, size spread, and how often boundaries cut sentences mid-thought. 100% client-side.

Turn RPM/TPM limits into a concrete request schedule — batch size, spacing, binding limit, and total run time, with a safety factor for retries. 100% client-side.

Check a JSON Schema against OpenAI structured-outputs strict mode rules — open objects, missing required keys, unsupported keywords — before the API rejects it. 100% client-side.

Estimate LLM token counts for any text or code - per-content-type heuristics (prose, code, JSON, CJK) with a ±15% range, plus chat-framing overhead. Runs entirely in your browser.

Build function-calling and MCP tool schemas that pass strict mode on the first try, and lint pasted ones against the strict-mode contract — additionalProperties, required-sync, defaults, enums — with one-click autofix for every mechanical violation. Runs entirely in your browser.

Estimate the VRAM an LLM needs — weights by quantization plus the KV cache for your context and batch — and see which consumer and datacenter GPUs hold it.

Encode text to Base32, Base58, Base62, or Ascii85 - or decode it back. UTF-8 safe, runs entirely in your browser, with a shareable link to your exact input.

Encode text to Base64 or decode it back. UTF-8 safe, runs entirely in your browser, with a shareable link to your exact input.

Build HTTP Basic Access Authentication headers from a username and password, or decode an existing Authorization header back to its credentials. UTF-8 safe and fully client-side, with a shareable link.

Compute SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text at once, using the browser's native SubtleCrypto. Copy each digest. 100% client-side.

Identify the likely hash algorithm of a hash string by its length and character set - MD5, SHA-1/2/3, BLAKE, CRC32, NTLM, bcrypt, Argon2 and more.

Convert text to hexadecimal and hex back to text, with delimiter options (none, spaces, 0x, backslash-x) and full UTF-8 support. 100% client-side.

Generate a keyed-hash HMAC (SHA-1/256/384/512) for a message and secret. Runs entirely in your browser via Web Crypto, with a shareable link to your exact input.

Encode text to HTML entities and decode entities back to text (named + numeric). UTF-8 safe, runs entirely in your browser, with a shareable link to your exact input.

Generate time-based one-time passwords (RFC 6238 TOTP) from a Base32 secret, with selectable algorithm, digit count, and period - updating live, entirely in your browser.

Percent-encode or decode URLs and query parameters. Choose component (encodeURIComponent) or full-URI (encodeURI) mode. 100% client-side.

Beautify, minify and validate JSON instantly. Paste, format, copy - all in your browser. Share a link to your exact input.

Project investment growth with any compounding frequency, scheduled contributions and inflation adjustment. Yearly breakdown, growth curve and CSV export — runs entirely in your browser.

Convert between digital data units - B, KB/KiB, MB/MiB, GB/GiB, TB/TiB. Switch between decimal (1000) and binary (1024) bases, runs entirely in your browser.

Compute screen pixel density (PPI/DPI), dot pitch, physical dimensions, and aspect ratio from any resolution. Solve for PPI from a diagonal, or derive the diagonal from a known PPI - all in your browser.

Convert between IPv4 and IPv6 addresses both ways. Parse and validate addresses, expand and compress IPv6 to its canonical RFC 5952 form, map an IPv4 into IPv4-mapped and IPv4-compatible IPv6 (or any custom /96 prefix), and extract an embedded IPv4 back out.

Paste any JSON and instantly get clean, typed TypeScript interfaces - primitives, nested objects, arrays and unions, all inferred. Optional keys, reserved-word quoting, and shape dedup are handled for you. Runs 100% in your browser.

Convert a JSON array of objects to CSV and back. Handles quoted fields, embedded commas, newlines and escaped quotes (RFC 4180). 100% in-browser.

Remove all whitespace from JSON for the most compact serialization. Validates as it minifies, runs entirely in your browser, with a shareable link to your exact input.

Generate Zod validation schemas from JSON. Infers z.string, z.number, z.boolean, z.object, z.array, z.null, and z.union for mixed arrays.

Transform a list between separators (newline, comma, space, pipe, semicolon, tab) with trim, dedupe, sort, and empty-removal options. Runs entirely in your browser, with a shareable link.

Compute the union, intersection, difference, or symmetric difference of two newline-separated lists. Deduped results with optional trim and case-insensitive matching. Runs entirely in your browser, with a shareable link.

Turn pipe, CSV, tab, semicolon, or space-separated data into a clean GitHub-Flavored Markdown table. Auto-detects the delimiter, pads columns, escapes pipes, and supports per-column alignment - all in your browser.

Evaluate math expressions - arithmetic, functions (sqrt, sin, log), comparisons, and constants (pi, e) - safely, in real time. Input is constrained to math-safe characters, fully client-side.

Compute monthly payments, the full amortization schedule and total interest, with extra-payment what-if analysis showing months and interest saved — runs entirely in your browser.

Convert numbers between binary, octal, decimal and hexadecimal. BigInt-powered, so it handles arbitrarily large values without precision loss.

Calculate percentages three ways - X% of Y, X is what percent of Y, and the percentage change between two values. Runs entirely in your browser, with a shareable link.

Convert internationalized domain names (IDN) between Unicode and Punycode (xn--) ACE form. RFC 3492 compliant, runs entirely in your browser, with a shareable link to your exact input.

Convert integers up to 3,999,999 to Roman numerals and back. Vinculum overline above 3,999, canonical-form validation, a step-by-step greedy breakdown, and 14 language sources. Runs entirely in your browser.

Compute IPv4 subnet details from a CIDR block - network, broadcast, host range, netmask, wildcard, host count, IP class, and private-range detection. Split a block into smaller subnets, all in your browser.

Convert XML to JSON and back, preserving attributes. Validates input and reports errors clearly, runs entirely in your browser, with a shareable link to your exact input.

Decode a JSON Web Token and inspect its header and payload as pretty JSON, with exp/iat claim awareness and an expiry badge. Runs entirely in your browser.

Test regular expressions against any text with all flags (g/i/m/s/u/y). See every match, its index and capture groups, plus the constructed pattern. 100% in-browser.

Validate credit card numbers with the Luhn checksum and detect the issuing brand (Visa, Mastercard, Amex, Discover, Diners, JCB, UnionPay, Maestro). 100% client-side - nothing is transmitted.

Validate email addresses one at a time or in bulk. Checks syntax, length limits, local-part and domain rules, plus-addressing, and IP-literal domains - all in your browser.

Validate International Bank Account Numbers (IBAN) with the mod-97 checksum, verify the country-specific length, and format the result. 100% client-side, no network.

Validate JSON and pinpoint errors with line and column numbers. Clear valid/invalid verdict plus the exact error location - runs entirely in your browser.

Estimate password strength with zxcvbn - realistic dictionary and pattern cracking with crack-time estimates and improvement suggestions. Runs entirely in your browser.

Translate a regular expression into plain English, step by step. Explains anchors, character classes, quantifiers, groups, escapes, alternation, and flags.

Parse, compare, and validate Semantic Versioning 2.0.0 strings. Check which of two versions is greater (with full prerelease precedence), test whether a version satisfies an npm-style range (^, ~, comparators, hyphen, ||), and bump major/minor/patch/prerelease. Runs 100% client-side.

Generate cryptographically-random passwords with a CSPRNG using rejection sampling (no modulo bias). Shows live entropy in bits, a 5-tier strength meter, average offline-GPU crack time, and a Pro mode with the entropy formula, a crack-time-vs-length curve, and a 4-scenario attack table. Everything runs locally - nothing is sent anywhere.

Generate RFC 4122 v4 UUIDs with crypto-grade randomness. Bulk generate, copy all, toggle format (uppercase / no hyphens).

Generate placeholder Lorem Ipsum text - paragraphs and sentences with adjustable counts. Classic Latin word pool, instant copy.

Generate random EUI-48 MAC addresses with a chosen separator, optional OUI prefix, uppercase formatting, and a locally-administered flag. Runs entirely in your browser with crypto-grade randomness.

Generate deterministic fake data (names, emails, numbers, dates, booleans, UUIDs, pick-from-list) from a schema and a seed. Reproducible output.

Turn any text or URL into a downloadable QR code. Full ISO encoder with all error-correction levels, versions 1-40, SVG and PNG export, colors and quiet-zone control — runs entirely in your browser.

Generate one or many random TCP/UDP port numbers across registered, ephemeral, or the full range - optionally unique. Runs entirely in your browser with crypto-grade randomness.

Build a standards-compliant robots.txt with per-user-agent allow/disallow rules, crawl-delay, and sitemap entries.

Generate cryptographically-secure random tokens in your browser. Pick the entropy size and format - hex, base32, base64, base62, or alphanumeric - and see the real strength in bits. Runs entirely client-side.

Generate Universally Unique Lexicographically Sortable Identifiers (ULID) - 26-character Crockford-base32 strings that sort by millisecond timestamp. Paste any ULID to decode its timestamp and randomness. Runs entirely in your browser.

Audit your real browser against 30 modern web capabilities - WebGPU, WASM, WebAuthn, Service Workers and more. Get a weighted readiness score, copy-paste detection snippets, and a shareable link.

Look up registration data for any domain, IP address, or ASN — straight from your browser to the authoritative RDAP registry over HTTPS. No backend, no database of lookups, fully private.

Pull URLs, emails, IPv4/IPv6 addresses, hashes (MD5/SHA-1/SHA-256/SHA-512), and domains out of logs, headers, or any pasted text.

Break any URL into its components - protocol, host, port, path, query params, hash, and credentials. Detects default ports and security at a glance, with a decode toggle for query values. Runs entirely in your browser.

Convert text between UPPER, lower, Title, Sentence, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and slug. Live, one-click copy.

Make URLs, IPs, and emails safe to paste by defanging indicators (https:// → hxxps[://], . → [.], @ → [@]) - and reverse refanged text back to its original form. Runs entirely in your browser, with a shareable link to your exact input and mode.

Find and replace text with literal or regular-expression matching, global replace, case sensitivity, whole-word, and capture-group substitution. Live match counter.

Encode text to HTML entities and decode entities back to text (named + numeric). UTF-8 safe, runs entirely in your browser, with a shareable link to your exact input.

Generate clean, URL-safe slugs from any text with locale-aware Unicode transliteration. Accents, emoji, and punctuation are handled automatically - runs entirely in your browser.

Alphabetize, reverse, shuffle, dedupe, or length-sort lines of text. Supports case-insensitive and natural sorting (file2 before file10).

Compare two pieces of text and see exactly what changed. Highlights added and removed lines, words, or characters, shows a per-side summary, and exports a unified diff you can paste into a PR or commit. Runs 100% in your browser.

Count words, sentences, paragraphs, characters, lines, and reading time, plus Flesch Reading Ease and Flesch-Kincaid grade-level readability scores.

Build campaign tracking URLs with utm_source, utm_medium and utm_campaign parameters. Bulk mode processes a whole list, presets and import round-trip existing tracking URLs, and a validator flags attribution-breaking values — runs entirely in your browser.

Live word, character, sentence, and paragraph counts plus reading-time estimate as you type.

Check WCAG 2.2 contrast ratio between any two colors with AA / AAA pass-fail for normal and large text, plus a live preview. For accessible, on-brand design.

Generate harmonious color palettes - complementary, analogous, triadic, tetradic, and monochromatic - from any base color. Export to CSS, Tailwind, or JSON.

Design and test CSS animations live - preview easing curves, durations, and keyframes, then copy the exact CSS.

Design layered CSS box-shadows with offset, blur, spread, color, and inset. Live preview and copy-ready CSS.

Pick a color and convert between HEX, RGB, HSL, HSV, and CMYK with a live preview. Edit any format and copy the rest - runs entirely in your browser.

Build linear, radial, and conic CSS gradients with multiple color stops and positions. Live preview and copy-ready CSS.

Create frosted-glass CSS - backdrop-blur, translucent background, subtle border, and soft shadow - with a copy-ready snippet and live preview.

Generate cryptographically-random passwords with a CSPRNG using rejection sampling (no modulo bias). Shows live entropy in bits, a 5-tier strength meter, average offline-GPU crack time, and a Pro mode with the entropy formula, a crack-time-vs-length curve, and a 4-scenario attack table. Everything runs locally - nothing is sent anywhere.

Encrypt and decrypt files with age — a modern, simple alternative to PGP. Password-based encryption runs entirely in your browser.

Hash passwords with Argon2id — the winner of the Password Hashing Competition. Configure memory, iterations, and parallelism. WASM-powered, client-side.

Hash a password with bcrypt or verify a password against an existing bcrypt hash. Configurable cost factor. Runs entirely in your browser.

See exactly what websites can learn about your browser without cookies — screen, GPU, fonts, timezone, language, and more. Educational, not tracking.

Paste a PEM X.509 certificate and see its subject, issuer, SAN, validity, key usage, fingerprints, and chain details in a human-readable format.

Drag and drop a file to compute its MD5, SHA-1, SHA-256, and SHA-512 checksums. Paste an expected hash to verify integrity - detect tampered or corrupted downloads instantly. Runs entirely in your browser.

Build a Content-Security-Policy header interactively. Toggle directives, add sources, see the assembled header in real time — with a security score that flags unsafe sources.

Generate a Certificate Signing Request and private key pair entirely in your browser. Download the CSR and key as PEM files.

Make URLs, IPs, and emails safe to paste by defanging indicators (https:// → hxxps[://], . → [.], @ → [@]) - and reverse refanged text back to its original form. Runs entirely in your browser, with a shareable link to your exact input and mode.

Sign messages with Ed25519 or ECDSA and verify signatures. Prove authorship without revealing your private key.

Build the three email-authentication DNS records — SPF, DKIM, and DMARC — as ready-to-paste TXT values, or look up a domain's live records over DNS-over-HTTPS. Import existing records, catch publishing mistakes, share via URL. Entirely client-side.

Paste raw email headers to trace the message path, detect spoofing, and check SPF/DKIM/DMARC authentication results. Runs entirely in your browser.

Visualize the randomness quality of any data. See Shannon entropy, byte frequency distribution, chi-squared score, and a visual entropy heatmap.

View and strip GPS, camera, date, and software metadata from photos entirely in your browser. Download a clean copy.

Encrypt or decrypt any file with AES-256-GCM in your browser. Password-based, zero server contact. Drag, drop, done.

Compute SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text at once, using the browser's native SubtleCrypto. Copy each digest. 100% client-side.

Generate a keyed-hash HMAC (SHA-1/256/384/512) for a message and secret. Runs entirely in your browser via Web Crypto, with a shareable link to your exact input.

Hide a secret message inside a PNG image or extract a hidden message from one. Uses least-significant-bit encoding with optional AES encryption.

Generate time-based one-time passwords (RFC 6238 TOTP) from a Base32 secret, with selectable algorithm, digit count, and period - updating live, entirely in your browser.

Generate memorable, high-entropy passphrases from the EFF diceware wordlist using cryptographic randomness. Each word is drawn with crypto.getRandomValues and rejection sampling (no modulo bias), and every passphrase shows its exact entropy in bits plus the estimated crack time at 1 trillion guesses/sec. Everything runs locally - nothing is sent anywhere.

Check if a password has appeared in known data breaches using k-anonymity. Only the first 5 characters of the SHA-1 hash are sent - your full password never leaves your browser.

Estimate password strength with zxcvbn - realistic dictionary and pattern cracking with crack-time estimates and improvement suggestions. Runs entirely in your browser.

Build a Permissions-Policy header interactively. Control which browser features (camera, microphone, geolocation, etc.) your site can use.

Encrypt or decrypt messages with PGP public/private keys. Powered by OpenPGP.js, runs entirely in your browser.

Generate PGP key pairs (ECC or RSA) in your browser. Download your public and private keys. Powered by OpenPGP.js.

Paste text and automatically detect and mask personal data — emails, phone numbers, IP addresses, SSNs, credit card numbers, and dates.

One number for your privacy health: your browser fingerprint, a test password's strength and breach exposure, and a site's security headers — four checks, one score, concrete fixes. Runs in your browser; only a 5-character hash prefix ever leaves it.

Generate cryptographically-secure random tokens in your browser. Pick the entropy size and format - hex, base32, base64, base62, or alphanumeric - and see the real strength in bits. Runs entirely client-side.

Paste HTTP response headers to analyze security posture. Checks CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy.

Split a secret into N shares where any K shares can reconstruct it — but fewer than K reveal nothing. Based on Shamir's threshold scheme over GF(256).

Generate Ed25519 or RSA SSH key pairs in your browser. Copy or download the public and private keys. No server involved.

Encrypt or decrypt text with a password using AES-256-GCM. Share the ciphertext safely - only someone with the password can read it.

Generate Curve25519 key pairs for WireGuard VPN configuration. Derives the public key from a clamped private key with a pure-BigInt RFC 7748 Montgomery ladder, optionally generates a pre-shared key, and renders a ready-to-edit wg-quick config template. Everything runs 100% client-side - keys never leave your browser.

Run real SQL on sample datasets - or your own schema - right in the browser. Write queries, see formatted results instantly, and export or share them. Powered by sql.js (SQLite WASM); 100% client-side.

A searchable, filterable reference for all 128 ASCII code points. See the decimal, hex, octal, and binary form of every character, narrow to printable characters only, clamp the code-point range, and click any row to copy. Runs 100% client-side.

Perform AND, OR, XOR, NOT, shifts and rotates on 8/16/32/64-bit values with exact bigint math. Enter operands in binary, octal, decimal or hex and read the result in every base plus a live bit grid. Runs 100% in your browser.

Compute Unix file permissions between octal (e.g. 755), symbolic (rwxr-xr-x), and decimal - including setuid, setgid, and sticky bits. Toggle permissions interactively, fully client-side, with a shareable link.

Translate any 5-field cron expression into plain English, build one field-by-field, and preview the next time it will fire. Supports steps, ranges, lists, and named days/months. Runs 100% in your browser.

Turn CSV data into SQL import statements: batched multi-row INSERTs, a Postgres COPY FROM STDIN block, or a MySQL LOAD DATA statement. Infers numeric columns, emits NULL for empty fields, sanitizes and de-duplicates header names into SQL identifiers.

Paste CREATE TABLE DDL and get an ER diagram as SVG: tables with typed columns, primary keys, and foreign-key arrows in a deterministic layered layout. Pan and zoom the live diagram; export the SVG.

A searchable reference for every HTTP request method - GET, POST, PUT, PATCH, DELETE, and more. See at a glance which are safe, idempotent, and cacheable, then compare any two methods side by side.

Searchable reference of all HTTP status codes with meaning, category, and usage notes.

Convert a JSON array of objects into SQL INSERT statements. Properly escapes strings, handles nulls, booleans, numbers, nested objects, and multi-row inserts.

Build valid JSON-RPC 2.0 requests, notifications, success responses, and error responses, plus batch arrays. Validate message structure.

A searchable map of common file extensions to their MIME types - text, image, audio, video, application, font, and multipart. Look up by extension or by type, filter by category, and copy the exact Content-Type string for any format.

Compute descriptive statistics - count, sum, mean, median, mode, min/max, range, variance, standard deviation, and quartiles (Q1/Q3/IQR) - from any list of numbers. Tolerates mixed separators and flags unparseable tokens. Choose sample (n−1) or population (n) variance. Everything runs 100% client-side.

Convert Unix epoch timestamps to human-readable dates and back. See seconds, milliseconds, ISO 8601, UTC, local and relative time at once.

Turn one image into the full web app icon set — favicon, apple-touch-icon and manifest sizes as crisp PNGs. Letterboxed contain-fit, optional white background — runs entirely in your browser.

Split an animated GIF into PNG frames with per-frame delays — decoded by our own pure GIF parser, entirely in your browser. Nothing uploads.

Shrink image file sizes entirely in your browser — fixed quality or an automatic fit to a size budget, optional max-dimension resize, batch support. Nothing uploads.

Convert images between PNG, JPEG and WebP entirely in your browser. Batch-friendly with quality control and a before/after size delta — nothing is uploaded.

Batch-resize images by width, height or percentage and stamp a text watermark with position, opacity and size control — entirely in your browser, nothing uploaded.

Split an image into an even grid of tiles — rows × columns with a live cut-line preview and per-tile or bulk PNG download. Runs entirely in your browser.

Inspect audio, video and image files at the byte level — MP4 boxes, ID3 tags, WAV chunks, GIF headers — parsed by our own readers, entirely in your browser.

Extract the dominant colors from any image as a reusable palette — median-cut quantization with population shares, hex and rgb, copyable — runs entirely in your browser.

Combine photos side by side, stacked, or in a grid — uniform cells, adjustable gap, one PNG out. Runs entirely in your browser.

Convert a video clip to an animated GIF — frame capture, palette quantization and GIF encoding all run locally with our own encoder. Nothing uploads.