Free Dev Tools

Test JavaScript-style regular expressions in your browser: enter a pattern, toggle global (g), case-insensitive (i), and multiline (m), paste sample text, and see highlighted matches with start indexes. Invalid patterns show a clear error. No signup; your strings stay on your device.

Encode plain UTF-8 text to Base64 or decode Base64 back to text in your browser (whitespace ignored when decoding). Swap encode/decode, copy the result, or upload a file in encode mode to extract the raw Base64 payload from a data URL. Convert runs client-side only.

Pretty-print, minify, and validate JSON payloads.

Paste an original and a modified version, then Compare to see a unified diff: line-by-line with +/- prefixes and optional line counts, or word-by-word with highlights. Copy the plain-text diff, switch views anytime, or Clear. Uses the diff library in your browser — nothing is uploaded.

HTTP client in the browser: collections, environments, {{variable}} interpolation, Bearer/Basic/API key/OAuth2/custom auth, JSON/form/urlencoded/multipart/GraphQL bodies, pre-request scripts, history, and code snippets (fetch, Axios, Python, PHP, Go, cURL, C#, Ruby). Sends through Dynamic Duniya’s API proxy (30s timeout). Workspace in localStorage; optional cloud sync when signed in.

Generate MD5 (via local md5), SHA-1, SHA-256, SHA-384, and SHA-512 digests from typed text or a whole file. Toggle which algorithms to run, optionally compute HMAC-SHA with a secret (MD5+HMAC not supported in-browser). Uses Web Crypto for SHA/HMAC. Copy each hex result. Nothing is uploaded — hashing runs in your browser (HTTPS recommended for crypto APIs).

Simulate and visualize Token Bucket, Leaky Bucket, Fixed Window, Sliding Log, and Sliding Counter — interactive traffic patterns, compare mode, and code examples.

Switch CSV → JSON or JSON → CSV. RFC 4180–style CSV parsing (quoted fields, doubled quotes), delimiter choice for import (comma, semicolon, tab, pipe), optional header row or col1… keys, pretty or minified JSON, stats after convert. JSON → CSV needs a non-empty array of objects; union of keys becomes columns; output CSV uses commas. Upload .csv/.json, load examples, copy, or download output.json / output.csv — all client-side.

Convert JSON to YAML or YAML to JSON in the browser with js-yaml: JSON.parse + YAML dump (2-space indent, 120-char wrap) or yaml.load + pretty JSON (2-space indent). Debounced live conversion as you type, line numbers on both sides, Convert now, copy, and download output.yaml / output.json.

Paste or upload JSON and edit it with an auto-generated form — add array items, update fields, download valid JSON. No coding required; runs entirely in your browser.

Convert XML to JSON or JSON to XML in the browser with fast-xml-parser: attributes map to configurable-prefixed keys (default @), trimmed text nodes, optional compact output, optional UTF-8 XML declaration on JSON→XML, and a root wrapper for bare arrays or scalars. Convert on demand, character/node estimate, copy, download output.json / output.xml.

One-click case transforms: UPPER/lowercase, Title and Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, alternating caps, reverse characters, and collapse extra spaces. Word-style cases split on spaces, underscores, hyphens, and common separators; camel/snake/kebab also split camelCase boundaries. Live character/word counts; Copy output or Use as input to chain styles — all in your browser.

Live stats as you type: words (whitespace-separated, optional case-insensitive folding), characters with/without spaces, sentences (. ! ?), paragraphs (blank-line breaks), lines, unique words, average word length, reading time (~200 wpm) and speaking time (~130 wpm), top 10 words with frequency bars, and keyword/phrase occurrence search. All client-side.

Generate random passwords in the browser with crypto.getRandomValues: length 8–128, toggles for uppercase, lowercase, digits, and symbols (!@#$%^&*), optional exclusion of ambiguous characters (0, O, I, l, 1), extra per-character exclusions, one-click regenerate, batch of five, copy, and a simple length/charset strength meter. Nothing is sent to a server.

Analyze a password locally: 0–100 score and tier (Very Weak → Very Strong), checklist for length, character classes, weak-list match, and simple pattern regex (123, abc, password, etc.), actionable suggestions, rough crack-time estimate assuming ~1B guesses/sec and naive charset size — optional show/hide. Nothing is uploaded.

Convert in the browser across eight categories: length, weight (metric + US customary), temperature (°C / °F / K via Celsius base), area, volume (metric + US kitchen), speed, time, and digital data (bits and bytes with binary KB–TB = 1024^n). Pick from/to units, swap, live result with formula line and per-category reference tips — no network.

Upload JPG, PNG, or WebP (max 5 MB) and extract 6–16 dominant colors in the browser: quantized buckets, sampled pixels, hex and RGB per swatch, copy hex, and download a palette.png strip. No server upload — previews and extraction stay on your device.

Convert colors in the browser: RGB ↔ Hex with live preview and copy buttons; HSL ↔ Hex with hue/saturation/lightness sliders; or paste hex, rgb(), or hsl() in All formats to emit hex, rgb/rgba, hsl/hsla, and a sample CSS variable line. Three-digit hex expands automatically — no server calls.

Compute WCAG 2.x contrast from two sRGB colors in the browser: pick foreground and background (color picker, hex, or 0–255 RGB), swap them, preview sample text sizes, see ratio to two decimals, and Pass/Fail for AA/AAA normal and large text. Optional hex hint when AA normal fails — no upload.

Build QR codes in the browser: URL, text, mailto, tel:, SMS (sms:), WhatsApp (wa.me), geo: coordinates, Wi‑Fi join strings, or vCard 3.0. Pick size 128–1024 px, error correction L–H, colors; copy payload, copy PNG, or download PNG/SVG. Tabbed UI with icons; custom strings via Text — no upload.

Free on-page and technical SEO check for one URL at a time — meta tags, headings, images, links, Open Graph, JSON-LD, and more. We do not include backlinks, keyword rankings, or full-site crawls (those need separate databases). URL mode: server HTML fetch + in-browser audit; optional PageSpeed from Google (capped per browser per day). Paste HTML: 100% in your browser.

All-in-one epoch tool in the browser: live second clock, epoch → GMT/local/relative/ISO 8601/RFC 2822 with auto or forced seconds through nanoseconds, date → epoch (YYYY-MM-DD HH:MM:SS style), start/end of year month or day, seconds → duration breakdown, shareable ?t= links, preferences in localStorage, and collapsible code snippets in 25 languages.