Tools tagged "conversion"

Convert audio files to mp3 / wav / m4a / ogg / flac. ffmpeg.wasm picks an encoder based on the chosen extension and re-encodes the file entirely in your browser. Supports batch processing and a single ZIP download.

Convert stereo audio between L/R and the classic M/S representation, where Mid = (L+R)/2 captures the centre information (vocals, kick, bass) and Side = (L-R)/2 captures the stereo difference (reverb tails, panned elements). M/S is the backbone of mid-side EQ and mid-side compression — let your DAW apply EQ to the centre while the sides stay untouched. Pick Mode (L/R → M/S or M/S → L/R), batch-process multiple files, save per-file WAV or download a ZIP. Round-trip is exact (M+S = L, M-S = R) so an EQ pass on the Mid channel can be folded back into the original L/R. Audio stays in your browser.

Decode .avif images with the browser-native AVIF decoder and re-encode them as JPEG / PNG / WebP. AVIF is great for the web but older Safari versions, email clients, Slack and Office still can't preview it — convert before sending. Batch conversion with single-click ZIP download is supported. Files never leave your device — everything runs in the browser.

Convert text to and from Base32 (RFC 4648 / TOTP 2FA secrets) and Base58 (Bitcoin addresses). Switch the variant (Base32 / Base58) and direction (encode / decode). UTF-8 byte based, so Japanese and emoji round-trip. Runs entirely in your browser.

Convert between text and binary. Pick a mode (text → binary or binary → text). Text is encoded to UTF-8 bytes and each byte is shown as a zero-padded 8-bit binary number (emoji and non-Latin text convert correctly as multiple bytes). Toggle space separators via an option; on decode, spaces and newlines are ignored and the input is regrouped into 8-bit bytes. Everything runs in your browser — your input is never uploaded.

Calculate your Body Mass Index from height and weight, with the classification under either the Japan Society for the Study of Obesity (JASSO) standard or the WHO standard. The result includes the ideal weight (BMI 22), the healthy weight range (BMI 18.5–25), and the difference from the ideal. Toggle the standard with a Mode, and the unit system between metric (cm / kg) and imperial (inch / lb) with an Option. Live computation as you type — everything stays inside your browser.

Convert Linux / macOS file permissions between octal (755 / 0755 / 4755) and symbolic form (rwxr-xr-x / rwsr-xr-t), or edit them directly with the owner / group / other checkboxes. Supports the setuid / setgid / sticky bits and accepts ls -l output with a leading file-type char (-, d, l, ...). Includes common presets such as 644 (regular file), 755 (directory or executable), 600 (SSH key), and 1777 (shared directory like /tmp). Runs entirely in your browser.

Cross-reference clothing sizes across Letter (XS / S / M / L / XL / XXL / 3XL), Japan (号 or cm), US, UK and EU. Switch between four charts (Men × Women × Tops × Bottoms) — tops use chest, bottoms use waist, both shown with the body measurement in cm. Useful when shopping at Amazon US / ASOS / H&M / Marks & Spencer from Japan or vice versa. Type a value to highlight the matching row. Tables are a composite of UNIQLO / MUJI / Marks & Spencer / H&M, with the usual 0.5–1 size brand variation (see FAQ). Runs entirely in your browser — no uploads.

Convert colors between HEX, RGB, HSL, and HSV in real time with a built-in color picker. Edit any field and the other three update instantly. Runs entirely in your browser — your color values never leave the page.

Format CSS with two modes: pretty (indent 2/4/tabs, line breaks, one declaration per line) and minify (strip whitespace and line breaks). Built on css-tree (MIT) which parses any CSS into an AST and re-serializes it. Preserves @media / @supports / @keyframes / @font-face / @import at-rules, calc() / var() / custom properties (--var), vendor prefixes, and shorthands. Comments (`/* ... */`) are dropped by the css-tree parser. CSS-in-JS placeholders (`${expr}`) cannot be parsed — pass plain CSS only.

Convert CSS font-size units in all directions at once. Type **1.5rem** and see **24px / 1.5em / 18pt / 150%** instantly. The root font-size (default 16px) is adjustable via slider (10–32px) for Tailwind/Bootstrap (16px), Material (14sp), or custom design-system bases. A **common rem-value cheat sheet** (0.25–4) is shown alongside for quick reference. Useful when migrating between rem/px-based design tokens, building responsive type scales, or mapping Tailwind text-* utilities to actual pixels.

Re-encode CSV and text files between Shift_JIS (CP932), UTF-8, UTF-16LE and EUC-JP — fix Excel's mojibake on UTF-8, hand UTF-8 text to legacy systems that need Shift_JIS, or add BOM so Excel reads UTF-8 correctly. Add / remove BOM, swap newlines (CRLF / LF / CR), and auto-detect the input encoding. Batch convert and grab the result as a ZIP. Files never leave your device — everything runs in the browser.

Convert CSV to JSON or JSON to CSV in your browser. Pick the delimiter (comma / tab / semicolon), toggle the header row, and choose the JSON indent. Handles quoted fields with embedded commas, quotes, and newlines.

Paste a `.env` file (dotenv / Node.js / Vite / Docker / Cloudflare Workers) and the tool renders a **key/value table** with **type guess** (string / number / boolean / url / json / empty), comment handling (`#`), `export` prefix, single / double / triple-quoted multiline values, and **`${VAR}` expansion preview** using previously-defined keys. Errors are flagged per line. Export the parsed result as **JSON** or **YAML**. Useful for sanity-checking before pasting into a shell, auditing CI/CD env vars, or reconciling multiple `.env` files.

Convert durations between three formats: seconds (5400), clock (01:30:00), and human-readable (1h30m). Pick the output format and the input is auto-detected — even mixed formats on different lines. Bulk-converts multi-line input and reports skipped (unparseable) lines. Supports d/h/m/s units (1d = 86400 seconds). Runs entirely in your browser.

Convert between Gregorian years and Japanese eras (Meiji, Taishō, Shōwa, Heisei, Reiwa) with a mode toggle. Accepts year-only or full date input, handles 元年 (year 1) and era-boundary transitions like 2019-05-01 → Reiwa 1 (令和元年). No dictionary download required — runs entirely inside your browser.

Convert spreadsheet column letters (A, B, ..., Z, AA, AB, ..., AZ, BA, ..., XFD) and column numbers (1, 2, ..., 16384) in both directions. Process many entries at once — one per line. Use the Mode toggle to switch between letter → number and number → letter. Handy when working with VBA, Apps Script, openpyxl, or SheetJS where you need to map a column index to its bijective base-26 letter form. Runs entirely in your browser.

Convert between fractions (3/4, 1 1/2 mixed numbers) and decimals (0.75, 1.5, repeating decimals like 0.(3)). Finite decimals become exact reduced fractions; in approx mode, continued fractions yield approximations like π → 355/113; fraction → decimal recovers the repeating block with `()` notation. Handy for cooking recipes, imperial ↔ metric, and probability notation.

Free online fuel economy converter. Convert between MPG (US / UK), L/100km, and km/L instantly — perfect for translating a rental car's mpg dashboard or comparing JDM and EU spec sheets. Uses exact NIST factors (1 mile = 1.609344 km, 1 US gal = 3.785411784 L, 1 UK gal = 4.54609 L). Runs entirely in your browser — no uploads.

Convert animated GIFs to H.264/AAC MP4 videos. GIFs balloon quickly; MP4 (H.264) typically shrinks the file to 1/5–1/10 the size and plays inline on X (Twitter), Bluesky, Discord and other social platforms. ffmpeg.wasm runs entirely in your browser — GIFs never leave your device. Supports batch processing and a single ZIP download.