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TOOLBOX / TOOLS FOR DEVELOPERS & DATA

Small tools. Clear answers.

Format JSON, debug encoded values and clean text — with browser-based tools, worked examples and practical troubleshooting guides.

What are you working on?

Browse all 65 tools ↓
01 / DATA

Make sense of JSON

Validate an API response, compare payloads or turn records into a spreadsheet.

JSON tools →02 / DEBUG

Decode an API value

Inspect Base64, URL parameters and JWT claims. Decoding is not signature verification.

Encoding tools →03 / CLEANUP

Clean a list of text

Remove duplicate lines, compare versions and normalize text before the next step.

Text tools →

Everyday essentials

JSON Formatter / Minifier / ValidatorHOT Beautify or minify JSON; validation errors show the exact position JSON to CSV Export an array of objects to CSV, with a selectable delimiter JSON Diff Compare two JSON snippets; list added, removed and changed key paths Base64 Encode / DecodeHOT Convert text to Base64 or decode Base64 back to text, with full support for Chinese and emoji URL Encode / Decode Percent-encoding conversion for Chinese parameters and special characters JWT ParserHOT Parse the JWT header and payload, and check the expiry time Line Dedupe & Sort Remove blank lines and duplicate lines, optionally sort alphabetically Unix Timestamp ConverterHOT Convert timestamps to dates and back, auto-detecting seconds/ms, with UTC and local time zone toggle.
UNDERSTAND THE RESULT

Why did formatting change my JSON ID?

Reproduce the problem and find the step that loses precision.

Read the troubleshooting guide →

Encoding & Security15

Base64 Encode / DecodeHOT Convert text to Base64 or decode Base64 back to text, with full support for Chinese and emoji URL Encode / Decode Percent-encoding conversion for Chinese parameters and special characters Unicode Encode / Decode Convert between text and \uXXXX escape sequences UTF-8 Encode / Decode Convert between text and UTF-8 hex bytes Escape Encode / Decode Convert between URL percent-encoding and escape sequences MD5 Hash GeneratorHOT Compute the 32-character MD5 hash of text, with batch and case-toggle support SHA Hash Generator Compute SHA-1 / SHA-256 / SHA-384 / SHA-512 in one click HMAC Signature Compute an HMAC-SHA signature with a secret key, handy for API debugging CRC32 Checksum Compute the CRC32 checksum, commonly used for data verification Base32 Encode / Decode RFC 4648 Base32 encoding, often used for Google Authenticator keys JWT ParserHOT Parse the JWT header and payload, and check the expiry time UUID Generator Generate v4 random UUIDs in bulk, with formatting options Password GeneratorHOT Generate strong random passwords with a customizable character set and length Morse Code Converter Convert text to Morse code (.-) and back, supports Latin characters Hash Compare Compare a text hash against a given value to verify a downloaded file

JSON Tools14

JSON Formatter / Minifier / ValidatorHOT Beautify or minify JSON; validation errors show the exact position JSON Escape / Unescape Convert text to an escaped form safe to embed in code strings, or revert it JSON Diff Compare two JSON snippets; list added, removed and changed key paths Sort JSON Keys Recursively sort all object key names in alphabetical order JSON ⇄ String Convert between doubly-escaped strings and JSON JSON ⇄ XML Convert a JSON object into structurally equivalent XML XML ⇄ JSON Convert XML to JSON with the browser built-in parser JSON to CSV Export an array of objects to CSV, with a selectable delimiter CSV to JSON Parse CSV into an array of objects, with optional header row JSON ⇄ YAMLNEW Convert JSON to YAML and YAML to JSON; a hand-written parser covers common structures JSON to CodeNEW Generate TS / Go / Java / C# / PHP type definitions from a sample JSON Query Params ⇄ JSON Convert between a URL query string and a JSON object Cookie ⇄ JSON Parse a Cookie string into JSON, or join it back JSON ⇄ Properties Convert between JSON and Java Properties style key-value files

Code Formatters6

SQL FormatterHOT Format SQL with keyword casing and clause indentation HTML Beautifier Indent HTML by tag nesting; keep script and style contents untouched CSS Formatter / Minifier Beautify CSS with indentation, or minify to strip redundant whitespace in one click JS Beautifier / Minifier Indent JS by braces for beautifying; protect strings when minifying XML Formatter / Minifier Indent XML by tag nesting, or compress into a compact single line Nginx Config Formatter Line-break and indent by { } and ; to tidy up conf hierarchy

Text Tools10

Word & Character Counter Count characters, Chinese/English, lines, paragraphs, UTF-8 bytes and estimated reading time Text Diff Checker Find added and removed lines between two versions, side by side Line Dedupe & Sort Remove blank lines and duplicate lines, optionally sort alphabetically Case Converter Convert between UPPERCASE, lowercase, capitalize first, title case and sentence case Naming Style ConverterNEW Convert among camel / Pascal / snake / kebab / CONSTANT styles in one click Line Processing Batch add prefix/suffix and line numbers; remove or keep lines containing keywords Find & Replace Support plain text and regex, optional case-insensitive, replace everywhere Regex TesterHOT Highlight matches in real time, show capture groups, with g/i/m toggles HTML Entity Encoder / Decoder Convert between special characters and & < and other HTML entities Whitespace Cleaner Trim ends, collapse spaces, remove all whitespace, remove tabs, convert CRLF/LF

Converters8

Length Unit ConverterHOT Convert instantly between metric and imperial length units: mm, cm, m, km, inch, foot, yard, mile, nautical mile. Weight / Mass Converter Convert between milligram, gram, kilogram, ton, ounce, pound, jin and liang. Area Unit Converter Convert between square meter, square kilometer, hectare, mu, square foot and square mile. Volume Unit Converter Convert between milliliter, liter, cubic meter, US gallon, UK gallon and cubic foot. Storage Capacity Converter Convert between bit, B, KB, MB, GB, TB, PB, showing both 1000 (decimal) and 1024 (binary) results. Speed Unit Converter Convert instantly between m/s, km/h, mph, knot and ft/s. Base / Radix Converter Convert between 2/8/10/16 and any 2–36 bases, with BigInt for large numbers and grouped binary output. Unix Timestamp ConverterHOT Convert timestamps to dates and back, auto-detecting seconds/ms, with UTC and local time zone toggle.

Calculators7

Percentage CalculatorHOT Four common percentage tasks: what % A is of B, B% of A, percent change, and ratio allocation. Date Calculator Compute the days/weeks/months/years between two dates, and add/subtract days, months, years from a date. Mortgage / Loan Calculator Compare equal-installment vs equal-principal loans: monthly payment, total interest and total repayment from principal/annual rate/term. BMI Calculator Compute BMI from height and weight, classify by China standard and show the normal weight range. Age Calculator From birth date, compute age, virtual age, Chinese zodiac, constellation and days to next birthday. Discount Calculator From original price and discount, get the amount paid and savings, or reverse the discount rate from original and current price. Random Number Generator Generate numbers in a range with count, dedup and decimal options, using crypto-grade randomness.

Image Tools1

Image to Base64 Convert an image to a copyable data URI string, or paste Base64 back to preview the image

Run Code4

HTML Live Runner Write HTML+CSS+JS on the left, live preview in the iframe on the right. Run and clear supported. JavaScript RunnerHOT Write JS and hit run; captures console.log/warn/error output and shows execution time. CSS Live Preview Write CSS on the left and an editable HTML structure; see the rendered effect on the right in real time. Markdown Live Preview Lightweight Markdown rendering: headings/bold-italic/code/lists/quotes/links/images/hr/tables.

What you will find here

ToolBox collects 65 small, single-purpose utilities in eight groups: encoding and hashing (Base64, URL, Unicode, UTF-8, MD5, SHA, JWT), JSON processing (formatting, validation, conversion to CSV or YAML), code formatters (HTML, CSS, JavaScript, SQL, XML), text tools (letter case, regex testing, word counting, diffing), unit conversion (length, weight, temperature, data size), date and time calculators (Unix timestamps, date differences, working days), image tools (compression, resizing, format conversion) and a code runner that executes in the browser. Each page does one job, and none of them ask you to sign up.

Everything runs inside your browser

There is no server doing the work. When you paste a non-sensitive sample into a tool, the processing happens in JavaScript on your own machine. Tool processing is separate from website traffic measurement. Do not paste production secrets or customer data into an online page; use an approved offline workflow for sensitive work.

You do not have to take our word for it. Open your browser developer tools (F12, then the Network tab) and use any tool: you will not see a single outbound request carrying what you typed.

How to use the site

The site is maintained continuously. Tools are added as they get requested, and the blog documents how the site is built and how to get more out of each tool. If the tool you need is missing, tell us — the most frequently requested ideas ship first.