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Developer Tools

Everyday utilities for programmers: formatters, encoders, converters and testers. Data you paste is processed locally, which makes them safe to use with API responses and tokens.

Popular

Base64 Encoder and Decoder

Convert text and files to and from Base64

URL Encoder and Decoder

Percent-encode and decode URLs, query strings and form data

HTML Entity Encoder and Decoder

Escape HTML characters or decode entities back to plain text

JWT Decoder

Inspect JWT header, payload, claims and expiry safely

UUID Generator

Generate v4 and v7 UUIDs in bulk and inspect any UUID

Hash Generator

MD5, SHA-1, SHA-256 and SHA-512 for text, files and HMAC

Unix Timestamp Converter

Convert epoch time to dates and dates to timestamps

Number Base Converter

Binary, octal, decimal, hex and any base from 2 to 36

Cron Expression Generator

Build, explain and test crontab schedules

HTTP Status Codes

Searchable reference of every HTTP status code

User Agent Parser

Identify browser, OS, device and bots from any user agent

Chmod Calculator

Convert 755 to rwxr-xr-x and build chmod commands

Popular

JSON Formatter

Beautify, validate and minify JSON with exact error locations

JSON to CSV Converter

Turn JSON arrays into spreadsheet-ready CSV with flattened columns

CSV to JSON Converter

Parse CSV or TSV into clean JSON with automatic delimiter detection

XML Formatter

Pretty-print or minify XML and catch well-formedness errors

HTML Formatter

Re-indent or shrink HTML without breaking pre blocks and scripts

CSS Minifier

Shrink stylesheets safely or expand minified CSS for reading

JavaScript Minifier

Compress and mangle JS with Terser, or beautify minified code

Markdown to HTML Converter

Write Markdown, see it rendered and copy clean HTML

HTML to Markdown Converter

Turn HTML or copied web content into clean, readable Markdown

YAML to JSON Converter

Two-way YAML and JSON conversion with precise error messages

SQL Formatter

Beautify or minify SQL for MySQL, PostgreSQL, T-SQL and more

Regex Tester

Test JavaScript regex with live highlighting, groups and replace

All developer tools at a glance

Format JSON, encode Base64, test regular expressions, decode JWTs and generate hashes. Free developer tools that run locally in your browser.

  • Base64 Encoder and Decoder: Encode text or files to Base64 and decode Base64 back to text instantly. Full UTF-8 support, URL-safe mode, data URIs and clear errors. Free and private.
  • URL Encoder and Decoder: Percent-encode or decode URLs and query strings online. Choose encodeURIComponent, encodeURI or form encoding, convert many lines at once and inspect URL parts.
  • HTML Entity Encoder and Decoder: Escape HTML special characters or convert all non-ASCII text to named, decimal or hex entities, and decode any HTML entity back to text. Free and private.
  • JWT Decoder: Decode JSON Web Tokens in your browser: read the header, payload and claims with readable dates, check expiry and verify HS256 signatures. Private and free.
  • UUID Generator: Generate random v4 or time-ordered v7 UUIDs (GUIDs), up to 1,000 at once, with uppercase, braces and no-hyphen options. Validate and inspect any UUID too.
  • Hash Generator: Calculate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or files, create HMACs and compare against an expected checksum. Free, fast and fully private.
  • Unix Timestamp Converter: Convert Unix timestamps to readable dates and back. Auto-detects seconds, milliseconds and microseconds, supports every time zone and shows a live clock.
  • Number Base Converter: Convert numbers between binary, octal, decimal, hex and any base from 2 to 36. Big integers stay exact, every field updates live and invalid digits are flagged.
  • Cron Expression Generator: Build cron schedules with a visual editor or paste any crontab expression to read it in plain English, check for errors and see the next 10 run times.
  • HTTP Status Codes: Searchable list of every HTTP status code from 100 to 526, with plain-English meanings, common causes and fixes for errors like 403, 404, 500, 502 and 503.
  • User Agent Parser: See your browser’s user agent and client hints, or paste any user agent string to identify the browser, engine, operating system, device type and bots.
  • Chmod Calculator: Work out Linux and Unix file permissions with checkboxes. Convert between numeric (755) and symbolic (rwxr-xr-x) modes and copy the exact chmod command.
  • JSON Formatter: Format, validate and minify JSON online. Pinpoints syntax errors by line and column, sorts keys and shows a collapsible tree. Free, fast and private.
  • JSON to CSV Converter: Convert JSON arrays to CSV online. Flattens nested objects into dot-notation columns, quotes values correctly and previews the table. Free and private.
  • CSV to JSON Converter: Convert CSV to JSON online with a real RFC 4180 parser. Auto-detects the delimiter, handles quoted fields and line breaks, and infers numbers. Free.
  • XML Formatter: Format and minify XML online. Pretty-print with your choice of indentation, check that XML is well-formed and see parser errors by line. Free and private.
  • HTML Formatter: Beautify messy HTML with clean indentation or minify it safely. Keeps pre, textarea, script and style content intact. Free online HTML formatter.
  • CSS Minifier: Minify CSS online to cut file size, with safe shortenings and license comments kept, or beautify minified CSS back into readable code. Free and private.
  • JavaScript Minifier: Minify JavaScript online with Terser: compress, mangle names, drop console calls and keep license comments. Beautify minified JS too. Free and private.
  • Markdown to HTML Converter: Convert Markdown to clean HTML with a live preview. Supports GitHub Flavored Markdown tables, task lists and code blocks. Copy or download the HTML free.
  • HTML to Markdown Converter: Convert HTML to clean Markdown online. Paste code or copied web content, choose heading, list and code block styles, and get GitHub-ready tables. Free.
  • YAML to JSON Converter: Convert YAML to JSON or JSON to YAML online. Handles anchors, merge keys and multi-document files, with clear error messages and line numbers. Free.
  • SQL Formatter: Format SQL queries online for MySQL, PostgreSQL, SQL Server, Oracle, BigQuery and more. Choose keyword case and indentation, or minify to one line. Free.
  • Regex Tester: Test regular expressions online with live match highlighting, capture groups, a replace preview and a cheat sheet. JavaScript regex flavor. Safe and free.

Every tool on ToolsWorld is free, needs no account and works on phones, tablets and computers.

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