Free Online Developer Tools
Format, encode, generate, convert, and minify — all in the browser. Pick a tool below to get started.
JSON Formatter
Validate, beautify, and minify your JSON data with tree view and syntax highlighting.
URL Encoder
Quickly encode or decode URL components, parameters, and special characters safely.
Base64 Converter
Convert plain text or binary data to Base64 and back. Support for Data URIs included.
Hash Generator
Generate MD5, SHA-1, SHA-256, and other cryptographic hashes from text or files instantly.
QR Code Generator
Create customizable QR codes for URLs, text, contact info, and more with download options.
HTML Encoder
Encode and decode HTML entities to prevent XSS and display special characters safely.
UUID Generator
Generate unique identifiers (UUIDs) in various versions for your applications and databases.
Unix Timestamp
Convert between Unix timestamps and human-readable dates in multiple formats and timezones.
Markdown Viewer
Preview and convert Markdown to HTML with live rendering and syntax highlighting support.
URL Shortener
Shorten long URLs for easier sharing using free public APIs. No sign-up required.
Password Generator
Generate strong, random passwords with customizable length and character options.
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words for your designs and layouts.
Text Diff
Compare two texts side by side and highlight the differences between them instantly.
JSON to CSV
Convert JSON arrays to CSV format for spreadsheets. Handles nested objects and arrays.
CSV to JSON
Parse CSV data into JSON arrays instantly. Auto-detect delimiters and headers.
XML Formatter
Beautify, minify, and validate XML documents with proper indentation and syntax checking.
Regex Tester
Test regular expressions with real-time matching, highlighting, and capture group display.
File Size Calculator
Convert between file size units: bytes, KB, MB, GB, and TB with precision control.
Word Counter
Count words, sentences, paragraphs, and reading time in any text. Free online word count tool.
Character Counter
Count characters with and without spaces, words, and lines. Perfect for social media limits.
Text Case Converter
Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, and more.
HTML Minifier
Minify HTML by removing whitespace, comments, and optional tags. Reduce file size instantly.
CSS Minifier
Minify CSS by removing whitespace, comments, and redundant code. Optimize stylesheets instantly.
JS Minifier
Minify JavaScript by removing whitespace, comments, and shortening code. Reduce bundle size.
Time Zone Converter
Convert time between time zones worldwide. Compare multiple time zones and find the best meeting time.
AI Prompt Generator
Generate structured AI prompts by combining role, task, and tone templates for better results.
Readability Score
Analyze text readability with Flesch-Kincaid, Gunning Fog, and Coleman-Liau index scores.
UTM Builder
Build campaign URLs with UTM parameters (source, medium, campaign) for marketing analytics tracking.
SQL Formatter
Format and beautify SQL queries with proper indentation, keyword highlighting, and dialect support.
Unit Converter
Convert between units of length, weight, temperature, and shoe sizes with instant results.
Font Pair Preview
Preview Google Font pairings with live text samples. Find the perfect heading and body font combination.
About These Developer Tools
Building software means juggling dozens of small tasks that sit between actual coding. You need to format a messy JSON response before reading it. You need to Base64-encode a token for an API header. You need to check a regex against test strings before committing it. These tasks are simple on their own, but switching contexts to a terminal, installing a CLI package, or spinning up a REPL breaks your flow.
That is the problem this collection solves. Every tool listed above runs in your browser tab, right next to your editor. The JSON Formatter validates and pretty-prints your payload in a single paste. The Regex Tester highlights matches in real time so you can iterate without running your test suite. The Hash Generator produces MD5, SHA-1, and SHA-256 digests from text or files, which is handy when you need to verify a download checksum quickly.
If you work with data interchange, JSON to CSV and CSV to JSON handle the tedious conversion between the two most common tabular formats. The XML Formatter does the same for XML — indent, validate, or collapse in one click. For encoding tasks, the URL Encoder and HTML Encoder cover percent-encoding and HTML entity conversion respectively.
On the optimization side, the HTML Minifier, CSS Minifier, and JS Minifier strip comments, whitespace, and redundant characters from your source files. They are useful for quick one-off minification when you do not want to configure a full build pipeline. And for daily productivity, the Password Generator creates strong, random passwords, the UUID Generator produces v4 identifiers, and the Text Diff compares two blocks of text with highlighted differences.
Recent additions broaden the toolkit. The SQL Formatter beautifies SQL queries with dialect support, the Unit Converter handles length, weight, temperature, and shoe sizes, and the UTM Builder generates campaign URLs with UTM parameters. The Readability Score analyzer calculates Flesch-Kincaid, Gunning Fog, and Coleman-Liau indices, the AI Prompt Generator assembles structured prompts for AI tools, and the Font Pair Preview lets you preview Google Font pairings with live text samples.
Privacy matters when you paste code or data into an online tool. None of these tools send anything to a server. Your input stays in the browser tab and disappears when you close it. There is nothing to install, no account to create, and no usage caps. Bookmark this page and come back whenever you need a quick utility.