Online Tools

100+ free browser-based tools: JSON formatting, encoding, hashing, image and PDF conversion, QR codes, regex and network speed tests. No install needed.

Image Tools

Image CompressorCompress JPG / PNG images locally in your browser, with quality and resolution control.Image WatermarkAdd text or logo watermarks locally with tile, grid, center and corner layouts. Batch supported.ID Photo MakerLocal AI cutout, background colors and standard ID sizes — data never leaves the browser.Background RemoverAI cutout in your browser, export transparent PNG in one click.Image to ICOConvert images into multi-size ICO icons locally in your browser — nothing is uploaded.Image CropDrag to pick the area, with common ratios like 1:1 and 16:9 lockable. Nothing is uploaded.Image StitchCombine several images into one horizontally or vertically, with reordering, spacing, alignment and background control.Nine-Grid SplitterSlice one image into a 3×3 grid and post the tiles in order to reassemble the full picture.Image Format ConverterConvert between JPG / PNG / WebP EXIF Viewer / RemoverView or strip photo metadata Image to Base64Convert an image to DataURL or raw Base64, or turn Base64 back into a downloadable image. Drag and drop supported.Image PaletteExtract the dominant colours of an image as HEX values with their share, one click to copy.GIF MakerCombine multiple images into an animated GIF with adjustable frame delay, quality and loop. Fully local.Placeholder Image GeneratorGenerate a placeholder image with custom size, colors and text, downloadable as PNG or SVG.Color Converter & PickerHEX / RGB / HSL with screen picker Image to BitmapConvert images to grayscale and 1/2/4/8-bit bitmaps with thresholding, dithering and hex data export.

Developer Tools

Timestamp ConverterUnix timestamp and date converter UUID GeneratorBatch UUID / ULID / NanoID generator Hash CalculatorMD5 / SHA hashes for text and files Base64 / URL EncoderText and file encoding tools JWT DecoderDecode JWT header and payload Regex TesterLive match highlighting and replace Number Base ConverterConvert numbers between any bases from 2 to 36. Integers use BigInt so nothing is lost, and negatives, fractions plus 0x / 0b / 0o prefixes are supported.Crontab Expression ParserParse a cron expression and list its next five runs. Standard 5-field, second-precision 6-field and common aliases are supported, with a selectable time zone.TOTP Code GeneratorGenerate 6 or 8 digit TOTP codes (RFC 6238) from a Base32 secret, entirely in your browser. SHA1 / SHA256 / SHA512 and custom periods supported; paste an otpauth link to fill in the parameters.SQL FormatterFormat or minify SQL for MySQL, PostgreSQL, SQLite and SQL Server, with configurable keyword case and indentation.cURL to CodePaste a curl command and get fetch, axios, Python requests or Go code, with method, headers and body handled.Cheat SheetHTTP status codes and MIME types with keyword filtering.Dot Matrix Font GeneratorTurn text into dot-matrix glyph data with custom size, font, offset and padding; pack by row or column and export C51, A51 or hex arrays.Checksum CalculatorCompute CRC-8, CRC-16/MODBUS, CRC-16/CCITT, CRC-32 plus BCC, LRC and sums at once from hex or text input.Sign / Ones / Twos ComplementGet sign-magnitude, ones complement, twos complement, offset binary and unsigned readings for any integer and bit width.Code Formatter & MinifierFormat or minify HTML, CSS, JavaScript and JSON with the size change shown live.IEEE 754 Float InspectorSplit a float into sign, exponent and mantissa, or decode a bit pattern back to a number.Q Format Fixed-Point ConverterConvert between floats and Qm.n fixed point with two-complement binary, hex, quantisation error and range.px to rem ConverterConvert between px, rem, em, pt, vw and vh with configurable root font size and viewport.Meta Tag GeneratorGenerate title, description, keywords, Open Graph and Twitter card tags with a length check and preview.nginx location MatcherPaste location blocks and a URI to see which one nginx picks, with the full decision trail.curl Command BuilderBuild an executable curl command from a form with shell escaping, auth headers and form encoding handled.Base64 to FilePaste base64 or a data URL, detect the real type from the file header and download it.URL Slug GeneratorTurn a title into a URL-friendly slug: Chinese to pinyin, accents stripped, separators normalised..env to JSONConvert between .env and JSON in both directions, handling quotes, inline comments, and values that contain both equals signs and hashes.htpasswd GeneratorGenerate htpasswd lines for nginx and Apache basic auth with apr1, bcrypt or SHA-1, and verify a password against an existing line.traceparent Generator / ParserGenerate a W3C Trace Context traceparent header, or paste one to validate every field, plus a tracestate check.WebSocket TesterConnect to any ws or wss endpoint from the browser, send and read messages, and inspect the handshake, close codes and byte counters.

Text & Utilities

Text Stats & CaseWord counts and case conversion Encode / DecodeConvert between URL encoding, HTML entities, Unicode escapes and hex, with instant results and reverse decoding.Text StatisticsLive counts of characters, CJK characters, words, lines, paragraphs, UTF-8 bytes and reading time.Markdown PreviewSide-by-side live Markdown preview with GFM tables and task lists, plus sanitised HTML export.Date CalculatorDays between two dates, business-day counts, date offsets, and exact age in years, months and days.Password GeneratorGenerate strong passwords with the browser crypto RNG; tune length, character sets and count, with entropy and strength.Text DiffLine-by-line text comparison ASCII TableThe complete ASCII table (0-127) with lookup by character, code or control name, plus a string converter.Text to ImageRender text into an image with word wrap, adjustable size, color, background and font, and export as PNG.Text ConverterSimplified/Traditional Chinese, pinyin, naming styles, letter case and full-width conversion.Line ToolsDeduplicate, sort, drop blank lines, number or reverse lines with live output.HTML to MarkdownConvert an HTML snippet to Markdown with headings, lists, tables, code blocks, links and images.Lorem Ipsum GeneratorGenerate Lorem Ipsum placeholder text with configurable paragraphs, sentences and sentence length.

Data Formats

JSON FormatterFormat, minify and validate JSON JSON / YAML / TOML ConverterConvert between JSON, YAML and TOML, with syntax errors reported by line and column. Everything runs locally in your browser.YAML FormatterFormat, validate and convert YAML to JSON, or JSON to YAML. A handy tool for developer config files.XML ToolsFormat XML or convert between XML and JSON while keeping attributes and nesting.JSON to CSVConvert between JSON arrays and CSV in both directions, with configurable delimiter and header.Excel Table to HTMLPaste an Excel selection to generate a clean HTML table locally, then preview, download or copy the source.JSON DiffCompare two JSON documents by field path — additions, removals and changes at a glance.JSON Schema ValidatorValidate JSON against a JSON Schema and list every error with its location and reason.JSONPath TesterQuery JSON with JSONPath expressions and see matched paths and values live.JSON to Type DefinitionsTurn a JSON sample into TypeScript interfaces, Zod schemas, Python dataclasses or Rust structs.

PDF Tools

Merge PDFCombine PDFs into one Split PDFExtract, delete or split PDF pages Image to PDFTurn images into one PDF PDF to ImageExport every PDF page as PNG or JPG at three quality levels, with per-page or ZIP download.PDF Page ManagerRotate, delete and reorder PDF pages, add a watermark, then export a new file.

QR Codes

QR Code Generator & ScannerGenerate text / URL / WiFi / batch QR codes and decode QR images locally.QR Code DecoderRead the text or link inside a QR code image; the image never leaves your browser.Barcode GeneratorGenerate CODE 128, EAN-13, EAN-8, UPC, CODE 39, ITF-14 and more; export SVG or PNG.QR Code StylerCustom dots, corners, colours and a centre logo, exported as PNG or SVG for print.

Life Tools

BMI CalculatorCalculate your Body Mass Index (BMI) from height and weight, graded by Chinese adult standards with a normal weight range. Fully local.Random Groups / Name PickerEnter a list to randomly split groups, pick a name, or draw items. Uses cryptographically secure randomness.Percentage / Discount CalculatorFind a percentage, calculate a ratio, measure change, or work out a discount price — four calculators in one, fully local.Kinship Term CalculatorType a relationship chain (e.g. "father's older brother") and get the correct Chinese kinship term.Online CalculatorAn online calculator with arithmetic, parentheses, powers and scientific functions (trig, logarithm, root). Fully local.Chinese CalendarA perpetual calendar with Gregorian and lunar dates, solar terms, festivals and zodiac. Click a date for details.Countdown / Stopwatch / PomodoroA countdown timer, stopwatch and Pomodoro timer with an alert sound. Runs fully locally.Fortune Wheel / Dice / DrawA lucky wheel, dice roller and fortune draw to help you decide when stuck. Fully local.Online TeleprompterPaste your script and it scrolls smoothly, with speed, font size, mirror and fullscreen.Handheld LED BannerTurn your phone into a glowing LED sign: full-screen scrolling text with adjustable speed, size and colours, plus mirror mode.Unit ConverterConvert between twelve categories of units — length, area, volume, mass, temperature, speed, time, data, pressure, energy, power and angle — with every result shown at once.Random Number GeneratorGenerate random integers in a range with count, uniqueness and sorting, using cryptographically secure randomness.RMB Capital ConverterConvert an amount to Chinese RMB capital form, plus Chinese numeral conversion. Fully local.

Network Tools

Network Speed TestMeasure download and upload bandwidth on demand, with latency, jitter and a live throughput chart. Nothing is transferred until you press start.IPv6 Connectivity TestCheck IPv6 readiness the way test-ipv6 does: probe IPv4-only, IPv6-only and dual-stack hosts plus a large-packet transfer, then report a score out of 10, an itemised check list, your public addresses and their type (native, tunnel or NAT64).My IP and NetworkSee your public IP, address family and approximate location, plus browser, platform, timezone, screen and network type details.Network Latency ProbeSend several rounds of requests to this site and a set of public hosts, then report average, minimum, maximum, jitter and packet loss.Subnet CalculatorEnter a CIDR block for network and broadcast addresses, mask, usable range and host count.

System & Security

Chmod CalculatorTick permission bits for octal and symbolic notation, or decode 755 / rwxr-xr-x back.Crypto ToolsBcrypt hashing, AES-GCM text encryption and RSA key pair generation, all in the browser.User-Agent ParserParse a UA string into browser, engine, OS, device type and CPU architecture.HMAC CalculatorCompute an HMAC with SHA-1, SHA-256, SHA-384 or SHA-512 and output hex or Base64.DES / 3DES CipherEncrypt or decrypt with DES and 3DES in ECB or CBC mode with PKCS#7 padding.SM4 CipherEncrypt or decrypt with the Chinese national standard SM4 in ECB or CBC mode.

Label Tools

Label DesignerDesign label templates online TSPL PreviewPreview TSPL commands in real time Text to BitmapRender text into a dot-matrix bitmap and output hex / binary font data, ready for TSPL label printing.

Audio Tools

Audio EditorTrim, join and mix audio in the browser: drag out a selection, stitch clips into one track or layer them, then export WAV or MP3.White Noise GeneratorWhite, pink and brown noise plus nature sounds (rain, waves, fire) with mixing, for sleep, focus and relaxation.Online MetronomeA precise online metronome with adjustable BPM and time signatures, with accented downbeats. Runs locally.