Developer Tools — 76 Free Developer Utilities

Developer tools on LaiUse cover the everyday utilities every programmer, engineer, and web developer reaches for. Format JSON for debugging APIs, test regular expressions against sample input, encode/decode Base64 strings, generate UUIDs for database primary keys, parse cron expressions for scheduled jobs, and convert between YAML, TOML, CSV, and XML data formats. Every developer tool runs entirely in your browser — your code, configuration, and data never leave your device, which makes LaiUse ideal for working with sensitive API responses, internal configurations, or any code you don't want uploaded to a third-party server. All developer tools are free with no signup required.

All 76 Developer Tools

Base32 Encoder/Decoder

Encode and decode Base32 strings — RFC 4648 compliant. Works with any text input.

Base58 Encoder/Decoder

Encode and decode Base58 strings — Bitcoin alphabet, no confusing characters (0, O, I, l).

Base64 Encoder/Decoder

Encode or decode Base64 strings instantly. Works with text, files, and images — all processing done locally in your browser.

BBCode to HTML

Convert BBCode to HTML. Supports bold, italic, links, images, colors, sizes, and formatting tags.

Bulk Hash Generator

Generate hashes for multiple files at once. Supports MD5, SHA-1, SHA-256, SHA-512 — perfect for checksum verification.

Bulk UUID Generator

Generate multiple UUIDs at once. Export as JSON, CSV, or plain text for bulk data seeding and testing.

Case Converter

Convert text between case formats: camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, and more.

Color Blindness Simulator

Simulate how your images appear to people with different types of color blindness. Upload an image and see 8 vision types.

Color Picker

Pick colors and explore palettes. Convert between HEX, RGB, HSL, and HSV formats with a live color preview.

Cron Expression Generator

Convert natural language into cron expressions instantly. Type "every day at 9am" or "weekdays at 3pm" and get a valid cron expression.

Cron Expression Parser

Parse and validate cron expressions. See the next 5 execution times and understand what your cron job schedule means.

CSS Beautifier & Minifier

Format and minify CSS code instantly. Beautify messy stylesheets with proper indentation or compress CSS for production. All local.

CSV ↔ JSON

Convert CSV data to JSON and JSON back to CSV. Handles headers, quoted fields, and type inference.

Embed Base32 Encoder

Get embed code for the Base32 Encoder — RFC 4648 base32 on your site.

Embed Base58 Encoder

Get embed code for the Base58 Encoder — Bitcoin-style base58 on your site.

Embed Base64 Encoder

Get embed code for the Base64 Encoder — add free Base64 encode/decode to your site.

Embed BBCode Converter

Get embed code for the BBCode→HTML converter — for forum/documentation sites.

Embed Case Converter

Get embed code for the Case Converter — camelCase/snake_case/kebab-case for your site.

Embed Color Blindness Simulator

Get embed code for the Color Blindness Simulator — accessibility preview for your design site.

Embed Color Picker

Get embed code for the Color Picker — HEX/RGB/HSL conversions on your design site.

Embed Cron Expression Generator

Get embed code for the Cron Expression Generator — natural language → cron for your site.

Embed Cron Expression Parser

Get embed code for the Cron Expression Parser — explain cron strings to your users.

Embed CSS Beautifier

Get embed code for the CSS Beautifier — format/minify CSS on your site.

Embed CSV ↔ JSON

Get embed code for the CSV↔JSON converter — data format tools for your docs.

Embed Emoji Picker

Get embed code for the Emoji Picker — 500+ emojis for your community site.

Embed Hash Generator

Get embed code for the Hash Generator — add free MD5/SHA-256/SHA-512 to your site.

Embed HTML Beautifier

Get embed code for the HTML Beautifier — pretty HTML on your site.

Embed HTML Entities

Get embed code for the HTML Entities encoder/decoder — add to your dev docs.

Embed HTML Formatter

Get embed code for the HTML Formatter — beautify & minify HTML on your site.

Embed HTML Minifier

Get embed code for the HTML Minifier — shrink HTML for production on your site.

Embed JavaScript Beautifier

Get embed code for the JavaScript Beautifier — format/minify JS on your site.

Embed JSON → CSV

Get embed code for the JSON→CSV converter — flatten JSON to spreadsheets.

Embed JSON → XML

Get embed code for the JSON→XML converter — interchange tools for your docs.

Embed JSON Path Query

Get embed code for the JSON Path Query tool — JSONPath playground for your docs.

Embed Line Sorter

Get embed code for the Line Sorter — sort/dedupe/reverse text lines on your site.

Embed Lorem Ipsum Generator

Get embed code for the Lorem Ipsum Generator — placeholder text for your mockups.

Embed Markdown → HTML

Get embed code for the Markdown→HTML converter — let visitors convert MD to HTML.

Embed Regex Tester

Get embed code for the Regex Tester — add a free regex playground to your blog.

Embed Reverse String

Get embed code for the Reverse String tool — for language learning or puzzle sites.

Embed Slug Generator

Get embed code for the Slug Generator — URL-safe permalinks for your CMS.

Embed SQL Formatter

Get embed code for the SQL Formatter — beautify SQL queries on your blog.

Embed Text Diff

Get embed code for the Text Diff tool — let visitors compare texts on your site.

Embed Timestamp Converter

Get embed code for the Timestamp Converter — Unix/epoch conversions on your site.

Embed TOML ↔ JSON

Get embed code for the TOML↔JSON converter — config format tools for your docs.

Embed UUID Generator

Get embed code for the UUID Generator — add free UUID v1/v4/v7 to your site.

Embed Word Counter

Get embed code for the Word Counter — word/char/reading-time stats on your site.

Embed XML ↔ JSON

Get embed code for the XML↔JSON converter — interchange tools for your docs.

Embed YAML ↔ JSON

Get embed code for the YAML↔JSON converter — config format tools for your docs.

Emoji Picker

Browse and search 500+ emojis by category. Click to copy any emoji to clipboard instantly.

Hash Generator

Generate cryptographic hashes (MD5, SHA-1, SHA-256, SHA-512) from text or files. Verify file integrity instantly.

HTML Beautifier

Beautify HTML code with proper indentation using js-beautify.

HTML Entities Encoder/Decoder

Encode and decode HTML entities — convert special characters to HTML entity codes and back.

HTML Formatter

Format and prettify HTML code with proper indentation. Clean up minified HTML and make it readable instantly.

HTML Minifier

Minify HTML by removing whitespace and comments.

JavaScript Beautifier & Minifier

Format and minify JavaScript code instantly. Beautify minified scripts or compress your JS for production. Supports ES6+, async/await, and template literals. All local.

JSON Formatter

Format, validate, and prettify JSON data. Minify JSON, sort keys, and explore nested structures with a tree view.

JSON Path Query

Query and extract data from JSON using JSONPath expressions. Explore nested structures, filter arrays, and get results instantly.

JSON to CSV Converter

Convert JSON data to CSV format. Flatten nested objects, handle arrays, download as .csv file.

JSON to XML Converter

Convert JSON to XML format. Generate valid XML documents from JSON data for easy integration.

JWT Decoder

Decode and inspect JSON Web Tokens (JWT). View header, payload, and signature — verify token claims without sending data anywhere.

Line Sorter & Deduplicator

Sort lines alphabetically, remove duplicates, reverse order, or shuffle. Perfect for cleaning lists.

Lorem Ipsum Generator

Generate placeholder text instantly. Choose sentence count, paragraph count, and format — perfect for design mockups and prototyping.

Markdown to HTML

Convert Markdown to HTML. Supports headers, bold, italic, links, lists, code blocks, blockquotes, and more.

Page Size Checker

Measure any webpage HTML size — total bytes, script/style/whitespace breakdown, and resource counts.

Regex Tester

Test and debug regular expressions in real-time. See matches highlighted, capture groups extracted, and common regex patterns.

Reverse String

Reverse characters or words in any text. See a visual character map with position indices.

SQL Formatter

Format and minify SQL queries. Supports SELECT, INSERT, UPDATE, DELETE with proper indentation.

Text Diff/Compare

Compare two texts and see differences highlighted — added, removed, and unchanged lines side by side.

Timestamp Converter

Convert between Unix timestamps and human-readable dates. Supports multiple timezones and custom date formats.

TOML ↔ JSON

Convert between TOML and JSON formats. TOML is a minimal config file format easy to read and write.

UUID Generator

Generate UUIDs (Universally Unique Identifiers) instantly. Supports UUID v1, v4, and v7 formats.

Word Counter

Count words, characters, sentences, paragraphs. Get reading time, speaking time, and character frequency analysis.

XML ↔ JSON

Convert XML to JSON and JSON to XML. Uses browser DOMParser for accurate XML parsing.

YAML ↔ JSON

Convert between YAML and JSON formats. Supports nested objects, arrays, and all YAML data types.

Why use LaiUse Developer tools?

  • Free forever — No credit card, no signup, no hidden fees. All 76 tools are 100% free.
  • Privacy first — Most tools process data locally in your browser. Your files never leave your device.
  • No installation — Works on any modern browser, desktop or mobile. No downloads or extensions.
  • Instant results — No upload time, no waiting. Results appear as you type.
  • Standards compliant — Output matches industry standards and works with other tools.