Handy Online Tools

Everyday utilities in one place. Everything runs in your browser, so your data never leaves your device.

86 tools

• Base64 Encode/Decode

  Encode text to Base64 or decode it back, with full UTF-8 support for Chinese and emoji and a URL-safe option.

• File to Base64

  Convert images and any other file to Base64 or a Data URI, or turn Base64 back into a file to preview and download.

• URL Encode/Decode

  Percent-encode or decode URLs and query parameters, with full UTF-8 support and exact error positions.

• HTML Entities

  Escape < > & and other characters as HTML entities or decode them back. Supports all 2,125 named and numeric references, with a quick reference.

• Unicode Escape

  Convert text to \uXXXX, \u{…}, &#x…;, U+XXXX and other escapes or back, with each character’s code point and UTF-8 bytes.

• Text to Hex

  Convert text to UTF-8 bytes in hex or decode hex back to text, with strict UTF-8 validation that points at the bad byte.

• JSON Formatter

  Beautify, minify and validate JSON with precise line and column error locations.

• JSON Viewer

  Browse JSON as a collapsible tree, search keys and values, and copy any node’s JSONPath or value. Handles large files.

• JSON to YAML

  Convert JSON to YAML and YAML to JSON, keeping key order and pointing to the line and column of syntax errors.

• JSON to CSV

  Convert JSON to CSV and back, flatten nested objects, detect delimiters, and add a BOM so Excel opens Chinese text correctly.

• JSON to TypeScript

  Generate TypeScript interfaces or type aliases from sample JSON, merging array items into optional properties and union types.

• CSV Viewer

  View CSV and TSV files as a sortable, filterable table, with delimiter and Big5 detection. Files never leave your device.

• XML Formatter

  Beautify, minify and validate XML, keeping comments and CDATA, with line and column locations for syntax errors.

• YAML Formatter

  Validate and beautify YAML: consistent indentation and quotes, comments kept, and syntax errors pinned to a line and column.

• Markdown Table Generator

  Build Markdown tables in a grid editor or paste from Excel, Google Sheets or CSV, with column alignment and neat CJK-aware padding.

• JWT Decoder

  Decode a JWT’s header and payload, explain standard claims like exp and iat, and see whether it has expired. Decodes only; never verifies or uploads.

• Regex Tester

  Test JavaScript regular expressions live: highlight matches, list groups, preview replacements, with a syntax explainer and common patterns.

• Text Diff

  Compare two texts side by side or inline, with changed words highlighted, ignore whitespace or case, and copy a unified patch.

• Cron Parser

  Explain a cron expression in plain words, field by field, and list its next 10 run times in any time zone.

• SQL Formatter

  Beautify messy SQL queries for MySQL, PostgreSQL, SQL Server, SQLite, BigQuery and more, with keyword case and indent options.

• URL Parser

  Break a URL into scheme, host, port, path, query parameters and fragment, with IDN support and an editor that rebuilds the URL.

• Chmod Calculator

  Tick read, write and execute boxes to convert Unix permissions between octal (755, 644) and rwxr-xr-x, with ready-to-run chmod commands.

• String Escape

  Escape and unescape text for JSON, JavaScript, HTML, XML, CSV, SQL, shell and regex string literals, with error positions.

• Slug Generator

  Turn titles into URL slugs: strip accents, choose the separator and maximum length, and keep or drop Chinese characters.

• Meta Tag Generator

  Fill in a title, description and share image to generate SEO, Open Graph and Twitter card tags, with search result and social card previews.

• Word Counter

  Count characters, Chinese characters, English words, lines, paragraphs, sentences and reading time instantly.

• Case Converter

  Convert text to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case and more, all at once.

• Remove Duplicate Lines

  Remove duplicate lines from text, optionally ignoring case and whitespace, or list only the lines that repeat.

• Sort Lines

  Sort lines alphabetically, naturally (file2 before file10), by number or length, reverse them or shuffle them randomly.

• Find & Replace

  Find and replace text in bulk with case and whole-word options or regular expressions with $1 groups, with matches highlighted.

• Whitespace Cleaner

  Trim trailing spaces, collapse blank lines and repeated spaces, remove zero-width and non-breaking spaces, convert tabs and line endings.

• Lorem Ipsum Generator

  Generate Latin Lorem ipsum or Chinese placeholder text by paragraphs, sentences or words, as plain text or HTML paragraphs.

• Markdown Preview

  Preview Markdown live with GitHub Flavored tables, task lists and strikethrough, then copy the HTML or download .html and .md files.

• Traditional/Simplified Chinese

  Convert between Simplified and Traditional Chinese, with optional Taiwan phrases (软件 → 軟體) and Hong Kong variants.

• Chinese Number Converter

  Turn numbers into formal Chinese amounts for checks and receipts (壹仟零壹元整) or everyday numerals, and back again.

• ROC Year Converter

  Convert ROC (Minguo) years and dates to Gregorian and back, with formats like 113/05/01 and 1130501, plus weekday and zodiac.

• Full/Half-width Converter

  Convert full-width letters, digits, punctuation and spaces to half-width or back, choosing which kinds of characters to change.

• Pangu Spacing

  Automatically add spaces between Chinese and English text or digits, with every change highlighted and Markdown and code kept intact.

• Text Encoding Converter

  Fix mojibake and convert text files between Big5, UTF-8, GBK, Shift_JIS and other encodings, with automatic encoding detection.

• Hash Generator

  Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text at once, and check them against an expected value.

• Password Generator

  Create strong random passwords with your browser’s secure random generator. Pick the length and character sets, or make many at once.

• File Hash Checker

  Compute MD5, SHA-1, SHA-256, SHA-512 and more for files of any size, and verify them against a published checksum.

• HMAC Generator

  Compute HMAC-SHA256, SHA-384, SHA-512, SHA-1 and MD5 of a message with a secret key, and verify webhook or API signatures.

• Password Strength Checker

  See how easy a password is to guess, with crack-time estimates for several attack scenarios and tips to improve it. It never leaves your browser.

• UUID Generator

  Generate UUID v4, UUID v7, ULID and Nano ID in bulk, and validate any UUID to see its version and embedded time.

• QR Code Generator

  Turn a URL or any text into a QR code with custom colors, size and error correction, then download it as PNG or SVG.

• QR Code Scanner

  Scan a QR code from an image, a pasted screenshot or your camera. Reads URLs, WiFi, contacts and more, and never opens links on its own.

• WiFi QR Code

  Create a QR code that joins your WiFi network when scanned. Download it as PNG or SVG, or print a card for guests.

• Barcode Generator

  Create Code 128, EAN-13, UPC-A, Code 39, ITF-14 and other barcodes with automatic check digits, then download SVG or PNG.

• Random Number Generator

  Generate random whole numbers or decimals in any range, with options for count, no repeats, sorting and excluded values.

• Image Compressor

  Compress JPEG, PNG and WebP images in bulk with adjustable quality and max size, compare before and after, and see the space saved. Nothing is uploaded.

• Image Converter

  Convert images to JPG, PNG or WebP in bulk, with quality and a background color for transparent areas. Runs in your browser; nothing is uploaded.

• Image Resizer

  Resize images in bulk by percentage or width and height, keep the aspect ratio or use social media sizes, with sharp results. Nothing is uploaded.

• Image Cropper

  Crop images by dragging or typing exact values, with 1:1, 16:9 and other aspect ratios, plus rotate and flip. Runs in your browser; nothing is uploaded.

• EXIF Viewer & Remover

  See a photo’s camera settings, GPS location and serial numbers, then remove EXIF metadata in one click — JPEGs keep their exact quality. Runs in your browser; nothing is uploaded.

• Image Color Picker

  Click anywhere on an image to get its HEX, RGB and HSL color, with a magnifier, a history of picks and the image’s dominant colors. Runs in your browser; nothing is uploaded.

• Color Converter

  Convert colors between HEX, RGB, HSL, HWB, OKLCH and OKLab, with a color picker and WCAG contrast check.

• Contrast Checker

  Check the WCAG contrast ratio of text and background colors for AA and AAA, with alpha support and the closest passing color suggestions.

• Palette Generator

  Generate complementary, analogous, triadic and other palettes plus a 50–950 scale from one color, and export CSS variables or Tailwind config.

• Gradient Generator

  Design linear, radial or conic CSS gradients with color stops, angle and center, preview them live and copy the CSS, with optional OKLCH interpolation.

• CSS Unit Converter

  Convert between px, rem, em, pt, vw, vh, cm and other CSS units, with your own root font size and viewport size.

• Aspect Ratio Calculator

  Simplify a width and height to an aspect ratio like 16:9, work out a missing side from a ratio, and browse common ratios and resolutions.

• Unit Converter

  Convert length, weight, temperature, area, volume and speed to every unit at once, including Taiwan units like ping and catty.

• Ping Converter

  Convert Taiwan ping to square meters, square feet, jia, fen and hectares exactly, plus price per ping to price per square meter.

• Taiwan Catty Converter

  Convert Taiwan catty (jin), tael and mace to kilograms, grams and pounds, and market prices per catty to per kilogram.

• Data Size Converter

  Convert KB, MB, GB and TB side by side with KiB, MiB, GiB and TiB, plus bits and bytes, and see why a 1 TB drive shows 931 GB.

• Number Base Converter

  Convert integers between binary, octal, decimal, hex and any base from 2 to 36, with big numbers, negatives and two’s complement.

• Percentage Calculator

  Find a percent of a number, what percent one number is of another, percent change, and a value after a percent increase or decrease, with the formula shown.

• Discount Calculator

  Work out the sale price and savings for % off or Taiwan-style 折 discounts, including stacked discounts and spend-and-save coupons.

• Taiwan VAT Calculator

  Convert between amounts before and after Taiwan’s 5% business tax (VAT), rounded to whole NT$ the way uniform invoices are.

• Split Bill

  Split a bill evenly, by shares or by what each person ordered, with service charge, tax and tip, and see exactly who pays the leftover cent.

• Loan Calculator

  Work out monthly payments and total interest for a mortgage or loan, with equal payments or equal principal, grace periods, stepped rates and a full schedule.

• Compound Interest Calculator

  See how a lump sum and monthly contributions grow with compound interest, with a year-by-year table, a chart and the rule of 72.

• BMI Calculator

  Calculate your BMI from height and weight in metric or imperial units, with WHO and Taiwan adult categories and a healthy weight range.

• Unix Timestamp Converter

  Convert Unix timestamps to dates and back. Detects seconds or milliseconds and shows ISO 8601, relative time and multiple time zones.

• Date Difference

  Count the days, weeks, months and years between two dates or times, plus weekdays. ROC (Minguo) dates work too.

• Date Add/Subtract

  Add or subtract years, months, weeks, days or business days from a date, with the weekday, ROC date and month-end rules.

• Time Zone Converter

  Convert a time to cities around the world, with UTC offsets, daylight saving time and a 24-hour meeting planner.

• Age Calculator

  Find your exact age in years, months and days, plus the traditional Chinese age, next birthday, days lived and zodiac sign.

• Countdown Timer

  Run a timer (1, 5, 25 minutes or custom) or count down to a date, with pause, a sound alert, notifications and share links.

• Subnet Calculator

  Enter an IPv4 CIDR or netmask to get the network, broadcast, usable range and host count, split subnets, and work with IPv6 prefixes.

• Browser Info

  See your browser version, user agent, screen size, language, time zone and supported features, and copy it all for a bug report.

• HTTP Status Codes

  Look up every HTTP status code with its meaning, common causes and fixes. Search by number or keyword in English or Chinese.

• Keyboard Event Codes

  Press any key to see its JavaScript key, code, keyCode, location and modifiers, and watch IME composition events as you type.

• Random Picker

  Paste a list of names and fairly draw one or more winners, with optional weights, removal of past winners and a history of rounds.

• Team Generator

  Split a list of names into balanced random teams, with optional leaders and people to keep together or apart. Copy as text, Markdown or CSV.

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