Free Online Tools, Right in Your Browser

Free online Base64 encoder and decoder with full UTF-8 support. Convert text to Base64 or decode Base64 back to plain text instantly.

Write Markdown with a live sandboxed preview, then export clean HTML or the .md source.

Format, validate and minify JSON online. Pretty-print with 2 or 4 spaces, get precise error positions, and copy or download the result.

Run real SQLite queries in the browser: a demo database to explore, sample queries, and instant result tables. Powered by sql.js WASM.

Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text instantly via the Web Crypto API.

Generate cryptographically random strong passwords. Choose length, character sets and exclude look-alike characters.

Compress JPG, PNG and WebP images with a quality slider and optional resizing. No size limits, no queues.

Generate QR codes for URLs, text or any content. Customize size, colors and error correction, then download a crisp PNG. Static codes never expire.

Convert colors between HEX, RGB, HSL and HSV with a live preview. Pick a color or paste any CSS color value and copy the format you need.

Free online Base64 encoder and decoder with full UTF-8 support. Convert text to Base64 or decode Base64 back to plain text instantly.

Free online URL encoder and decoder. Percent-encode query parameters or encode complete URLs while preserving their structure.

Count words, characters, sentences and paragraphs in real time as you type. CJK-aware word counting and a reading-time estimate included.

Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case and kebab-case in one click.

Test JavaScript regular expressions live. See every match highlighted with capture groups, match indexes and instant syntax errors.

Write Markdown with a live sandboxed preview, then export clean HTML or the .md source.

Fix garbled Chinese text caused by wrong encodings. Tries UTF-8, GBK, Big5 and Latin-1 round-trip combinations.

Convert Chinese text to Pinyin (with or without tones) and Zhuyin/Bopomofo. Polyphonic characters handled by context.

Generate Lorem Ipsum paragraphs, sentences or words for design mockups — with or without the classic opening. Free and instant.

Convert Markdown to a print-styled document and save it as PDF through the browser print dialog — selectable text, crisp fonts.

Compare two texts line by line and see additions and deletions highlighted, with add/remove counters. Ignore case or edge whitespace when comparing.

Convert Chinese text between Simplified and Traditional, including Taiwan and Hong Kong variants with their local vocabulary (软件 → 軟體).

Format, validate and minify JSON online. Pretty-print with 2 or 4 spaces, get precise error positions, and copy or download the result.

Generate random UUID v4 and time-ordered UUID v7 identifiers in bulk, using the browser cryptographic random API. Copy one or all with a click.

Convert Unix timestamps to readable dates and back. Shows local time, UTC and ISO 8601, handles both seconds and milliseconds, with a live current-time display.

Decode JWT header and payload into readable JSON, with expiry and issue dates converted to human-readable form.

Parse and generate cron expressions online for Linux crontab, Spring @Scheduled and Quartz. Per-field breakdown, plain-language schedule and next run times.

Convert numbers between binary, octal, decimal, hex and any base from 2 to 36 instantly. Live results as you type.

Parse any User-Agent string into browser, engine, OS, device and CPU details. Your own UA is pre-filled.

Generate typed entity classes from JSON for TypeScript, Java, Go, C#, Python, Kotlin and Swift. Nested objects become separate classes.

Convert .xlsx files to CSV (per sheet) and CSV text or files back to Excel workbooks. Parsing via SheetJS.

Open huge log files (hundreds of MB) streamed in the browser, with instant level counts and keyword search.

Run real SQLite queries in the browser: a demo database to explore, sample queries, and instant result tables. Powered by sql.js WASM.

Format, validate and minify XML with a collapsible tree: pretty-print with 2/4 spaces or tabs, jump to syntax errors by line and column, copy or download the result.

Format and validate YAML (.yml) with a collapsible tree: normalize indentation, jump to syntax errors by line and column, multi-document files supported, plus a compact flow-style output.

Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text instantly via the Web Crypto API.

Generate cryptographically random strong passwords. Choose length, character sets and exclude look-alike characters.

Interactive demos of the birthday attack and brute-force preimage search on truncated hashes. Educational and hands-on.

Generate time-based one-time passwords (TOTP) from a Base32 secret or an otpauth:// URI: 6/8 digits, 30/60s periods, SHA-1/256/512, with the current code, its remaining seconds and the next code.

Compress JPG, PNG and WebP images with a quality slider and optional resizing. No size limits, no queues.

Generate QR codes for URLs, text or any content. Customize size, colors and error correction, then download a crisp PNG. Static codes never expire.

Draw a smooth handwritten signature with mouse, touch or stylus. Adjustable pen, undo, and transparent-background PNG export.

Add visible text watermarks (position/tile/opacity) and embed invisible LSB blind watermarks that can be extracted later.

Split an image into a 3×3 grid (or custom rows × columns) for social media feeds. Preview tiles and download them all.

Stitch multiple screenshots into one long image vertically or horizontally, with gap and background options.

Combine photos into one image on a three-pane workspace: layouts on the left, the collage canvas in the middle (upload per cell), canvas and export settings on the right. 35 layouts, drag a photo onto another cell to swap, Alt-drag to reposition, wheel zoom, arrow-key nudges, resizable dividers, background image/color, export PNG/JPEG up to 3072 px or copy to clipboard.

Extract EXIF metadata and GPS coordinates from photos: camera, lens, exposure settings and map links.

Turn any image into a complete favicon set: 16-256px PNGs, a multi-resolution .ico file, Apple touch icon and ready-to-paste HTML.

Rasterize SVG to PNG at any scale, or render long text into a styled PNG image. Perfect for code screenshots and share cards.

Convert a clip of MP4/WebM video to an animated GIF: pick start, duration, FPS and size, then download.

See the colors of any image as an interactive 3D point cloud in RGB space. Drag to rotate, scroll to zoom. Rendered with Three.js.

Read the contents of a QR code from an image: upload, drop or paste a screenshot and the decoded text appears with a link shortcut for URLs. Works with Wi-Fi, vCard and JSON payloads too.

Crop an image with a draggable, resizable selection and ratio presets (1:1, 4:3, 3:4, 16:9, 9:16, free). Live output preview with exact pixel dimensions, export as PNG or JPEG.

Convert colors between HEX, RGB, HSL and HSV with a live preview. Pick a color or paste any CSS color value and copy the format you need.

Convert font sizes between px, pt, em, rem and %, with a Chinese type-size reference table (初号 to 八号). Live results.

Build linear or radial CSS gradients visually: drag angle and colour stops, use presets, then copy the CSS or download the gradient as a PNG.

Check the WCAG contrast ratio between text and background colours, with AA/AAA verdicts for normal and large text plus a live preview.

Calculate network and broadcast address, subnet and wildcard masks, usable host range and address type from an IPv4 CIDR, and split the network into equal subnets.

Precise online stopwatch with lap times, plus a live world clock: analog dials for major cities with digital readouts and UTC offsets below.

Test every key on your keyboard online: see key codes, modifier states and a rolling press log. Nothing to install.

Test mouse buttons, wheel and tracking online. Live coordinates, click counters per button and a movement trail on canvas.

Fullscreen pure-color tests to find dead pixels and check uniformity, plus screen info: resolution, pixel ratio and color depth.

Calculate BMI (WHO/CN categories), body fat percentage (U.S. Navy tape method) and basal metabolic rate (Mifflin-St Jeor) with daily calorie needs.

Play white, pink or brown noise and pure-tone sound waves for sleep, focus or tinnitus relief. Generated live by Web Audio.

Free mortgage calculator for commercial, housing-fund and mixed loans: monthly payment, total interest and per-part breakdown. Fixed or decreasing repayment, common-rate presets, works by loan amount or home price.

Turn any image into a playable jigsaw puzzle (3×3 to 5×5) with a timer and move counter. Click two tiles to swap them.

Play a two-octave piano with your computer keys, mouse or a real MIDI keyboard. Web Audio synthesis with selectable waveforms.

Draw a floor plan: grid-snapped walls with auto dimensions, doors, windows and PNG export.

Set a countdown in hours, minutes and seconds, or pick a preset like 5 or 25 minutes, with a visual progress ring. A triple beep alarm plays when it reaches zero, and the tab title shows the remaining time.

Convert between units of length, weight, area, volume, temperature, speed, data storage and time — with an instant table of the value in every unit of the category.

Merge several PDFs in any order, extract a page range into a new file, delete pages, or rotate every page by 90/180/270 — files never leave the page.