Tools

Generate UUID v4 (random) or v7 (time-ordered, RFC 9562) — runs locally in your browser.

Convert Unix epoch (s, ms, µs, ns) or ISO 8601 strings between formats — runs locally.

Decode a JSON Web Token into header + payload. Highlights expiry, alg=none, custom claims — runs locally.

Paste any JSON to inspect it as a tree, copy any subtree by JSONPath, or format / minify — runs locally.

Build a JavaScript regex, see every match with capture groups, and preview replaceAll — runs locally.

Encode or decode text in base64, base64url, hex, and percent-encoded URLs — runs locally.

Compare two blobs of text — line, word, or character mode. Unified diff or inline view, runs locally.

Pick a foreground and background, see the WCAG 2.2 contrast ratio with AA/AAA badges, plus hex/rgb/hsl/oklch conversions. Runs locally.

Paste a cron expression to get a plain-English description and the next five fire times in UTC or local — runs locally.

Paste any URL — break it into scheme, host, path, query params, and hash. Edit any field, copy the rebuilt URL. Runs locally.

Paste any text or URL — get a scannable QR. Pick the ECC level (L / M / Q / H), copy the SVG, or download as PNG. Runs locally.

Compute SHA-1, SHA-256, SHA-384, or SHA-512 of any text — three encodings (hex, base64, base64url). Runs locally in your browser via WebCrypto.

Paste any JSON to infer a TypeScript interface tree or a Zod v4 schema — nested types, mixed-key merge, heterogeneous unions. Runs locally.

Convert between px, rem, em, pt, %, vw, vh, and ch. Re-anchor every row by editing root font, parent length, or viewport. Plus Tailwind v4 class matches — runs locally.

Encode text into HTML entities (named, &#xHEX;, &#DEC;), decode entities back to text, or inspect every codepoint — U+XXXX / UTF-8 bytes / JS escape / named entity. Runs locally.

Paste a YAML document to get pretty-printed JSON, or paste JSON to get canonical block-style YAML — 2-space indent. Runs locally in your browser.

Paste Markdown — see the rendered HTML side-by-side. GFM tables, task lists, strikethrough, fenced code. Sanitized via DOMPurify. Runs locally in your browser.

Paste a .env file to get a flat JSON object, or paste JSON to get canonical KEY=value lines. dotenv spec — quotes, escapes, $VAR refs preserved verbatim. Runs locally.

Paste a TOML document to get pretty-printed JSON, or paste JSON to get canonical TOML 1.0.0 output. Tables, arrays, dates, multi-line strings. Runs locally.

Paste a CSV or TSV table to get an array of JSON objects (header-row keyed, numbers + booleans coerced), or paste a JSON array to get RFC 4180 CSV. Delimiter auto-detected. Runs locally.

Paste an XML document to get a plain JS object (attributes prefixed `@_`, mixed-content text nodes under `#text`), or paste a JSON object with a single root key to get formatted XML. Runs locally.

Paste a JSON Schema (draft 7 or 2020-12) to project it into a TypeScript interface tree or a Zod v4 schema. Handles $ref, oneOf, allOf, enum, and format hints. Runs locally.

Paste any text — get the same words in thirteen canonical conventions: camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case, COBOL-CASE, Title / Sentence / lower / UPPER, dot.case, path/case, Header-Case. Splits on whitespace, punctuation, and camel/acronym boundaries. Runs locally.

Generate placeholder text — paragraphs, sentences, or just words. Toggle the canonical "Lorem ipsum dolor sit amet…" opener. Seed-deterministic: deep-link with ?seed=N reproduces the exact same output. Runs locally.

Drop any image — get the pixel dimensions, file size, and every EXIF / GPS / ICC tag the camera embedded. JPEG, PNG, WebP, HEIC, AVIF, TIFF, GIF. Runs locally in your browser — the file never leaves your machine.

Drop any image — get the dominant colors as a 3 / 5 / 8 / 12-swatch palette via k-means++. Each swatch comes with hex / rgb / hsl / oklch + pixel share. Export as CSS vars, Tailwind @theme, SCSS, JSON, or plain hex. Runs locally in your browser.

Drop one or more images — get the 64-bit DCT-based perceptual hash for each, plus the pairwise Hamming distance so you can spot near-duplicates that survive resizing, re-saving, or mild edits. Runs locally in your browser.

Paste any HTML to get React-ready JSX — class → className, for → htmlFor, tabindex → tabIndex, inline style strings → camelCased object literals, void elements self-closed, comments rewritten, SVG presentation attributes renamed. Inline event handlers emit JSX placeholders. Runs locally.

Paste two JSON blobs — get a semantic, key-order-independent diff. Adds, removals, value changes, and type changes tracked separately. Each row has a copyable RFC 6901 JSON Pointer; export the whole diff as an RFC 6902 JSON Patch. Arrays compared positionally. Runs locally.

Convert any text to URL-safe slugs — Unicode transliteration (Déjà Vu → deja-vu), punctuation strip, camelCase split, length cap that snips at the last separator boundary, optional reserved-word avoidance. Dash or underscore separator. One slug per input line. Runs locally.

Drop any image — resize, crop, or stretch to any pixel dimensions, then re-encode as JPEG, PNG, or WebP and download. Aspect-ratio presets (1:1, 16:9, 9:16, …), fit / fill / stretch modes, quality slider. Runs locally in your browser — the file never leaves your machine.