35 free online tools
Developer Tools
Everyday utilities for developers: JSON formatting and validation, Base64 encoding and decoding, all client-side.
JSON Formatter
Beautify, minify and validate JSON with clear error messages.
Open toolBase64 Encoder
Encode text or files to Base64, including data URLs.
Open toolBase64 Decoder
Decode Base64 strings and data URLs back to text.
Open toolURL Encoder & Decoder
Percent-encode or decode URLs and query parameters instantly.
Open toolUUID Generator
Create cryptographically random version 4 UUIDs in bulk.
Open toolHash Generator
Compute MD5, SHA-1, SHA-256 and SHA-512 digests from text.
Open toolTimestamp Converter
Convert Unix timestamps to dates and back, in UTC or local time.
Open toolHTML Minifier
Shrink HTML by removing whitespace, comments and noise.
Open toolCSS Minifier
Strip whitespace and comments to ship smaller stylesheets.
Open toolCSS Beautifier
Reformat minified CSS with clean indentation you can read.
Open toolJavaScript Minifier
Compress JavaScript by removing comments and dead whitespace.
Open toolJavaScript Beautifier
Reformat compressed JavaScript into readable, indented code.
Open toolHTML Beautifier
Indent messy HTML into a clean, readable document tree.
Open toolXML Formatter
Pretty-print and validate XML with clear error messages.
Open toolXML to JSON Converter
Turn any XML document into clean, formatted JSON.
Open toolJSON to XML Converter
Convert JSON objects and arrays into valid XML markup.
Open toolMarkdown Previewer
Write Markdown and see the rendered HTML update live.
Open toolRegex Tester
Test regular expressions with live highlighting and capture groups.
Open toolURL Parser
Break any URL into protocol, host, path, query and fragment.
Open toolUUID Validator
Check UUID formatting and identify the version and variant.
Open toolMIME Type Checker
Look up the MIME type for any file extension or filename.
Open toolRandom String Generator
Generate random strings, keys and IDs to your own recipe.
Open toolJWT Decoder & Validator
Decode, inspect, and validate JSON Web Tokens offline in your browser.
Open toolJWT Generator
Generate custom JWT tokens using HS256, HS384, or HS512 HMAC algorithms.
Open toolCron Expression Generator
Build 5-part cron expressions visually with live human-readable explanations.
Open toolCron Expression Parser
Parse cron expressions into plain English schedules and future execution dates.
Open toolSQL Formatter
Beautify, indent, and format SQL queries with customizable keyword casing.
Open toolSQL Minifier
Compress SQL code by stripping comments and unnecessary whitespace.
Open toolSQL to JSON Converter
Convert SQL INSERT statements or table queries into formatted JSON arrays.
Open toolJSON Diff Checker
Compare two JSON objects side-by-side and highlight additions, deletions, and edits.
Open toolYAML Formatter
Format, validate, and beautify YAML markup with syntax error checking.
Open toolYAML to JSON Converter
Convert YAML configuration files into formatted JSON instantly.
Open toolJSON to YAML Converter
Convert JSON payloads into clean, indented YAML configuration documents.
Open toolTOML to JSON Converter
Convert TOML configuration files into formatted JSON objects.
Open toolENV File Generator
Build, format, and manage .env environment variable files with ease.
Open toolAbout Developer Tools
The Developer Tools collection provides browser-based utilities designed for high performance, local data processing, and complete privacy. Every tool operates entirely within your browser - no server uploads, no watermarks, and no signups required.
| Tool Name | Key Functionality | Client-Side Processing | Usage Limit |
|---|---|---|---|
| JSON Formatter | Beautify, minify and validate JSON with clear error messages. | 100% Local | Unlimited / Free |
| Base64 Encoder | Encode text or files to Base64, including data URLs. | 100% Local | Unlimited / Free |
| Base64 Decoder | Decode Base64 strings and data URLs back to text. | 100% Local | Unlimited / Free |
| URL Encoder & Decoder | Percent-encode or decode URLs and query parameters instantly. | 100% Local | Unlimited / Free |
| UUID Generator | Create cryptographically random version 4 UUIDs in bulk. | 100% Local | Unlimited / Free |
| Hash Generator | Compute MD5, SHA-1, SHA-256 and SHA-512 digests from text. | 100% Local | Unlimited / Free |
| Timestamp Converter | Convert Unix timestamps to dates and back, in UTC or local time. | 100% Local | Unlimited / Free |
| HTML Minifier | Shrink HTML by removing whitespace, comments and noise. | 100% Local | Unlimited / Free |
| CSS Minifier | Strip whitespace and comments to ship smaller stylesheets. | 100% Local | Unlimited / Free |
| CSS Beautifier | Reformat minified CSS with clean indentation you can read. | 100% Local | Unlimited / Free |
| JavaScript Minifier | Compress JavaScript by removing comments and dead whitespace. | 100% Local | Unlimited / Free |
| JavaScript Beautifier | Reformat compressed JavaScript into readable, indented code. | 100% Local | Unlimited / Free |
| HTML Beautifier | Indent messy HTML into a clean, readable document tree. | 100% Local | Unlimited / Free |
| XML Formatter | Pretty-print and validate XML with clear error messages. | 100% Local | Unlimited / Free |
| XML to JSON Converter | Turn any XML document into clean, formatted JSON. | 100% Local | Unlimited / Free |
| JSON to XML Converter | Convert JSON objects and arrays into valid XML markup. | 100% Local | Unlimited / Free |
| Markdown Previewer | Write Markdown and see the rendered HTML update live. | 100% Local | Unlimited / Free |
| Regex Tester | Test regular expressions with live highlighting and capture groups. | 100% Local | Unlimited / Free |
| URL Parser | Break any URL into protocol, host, path, query and fragment. | 100% Local | Unlimited / Free |
| UUID Validator | Check UUID formatting and identify the version and variant. | 100% Local | Unlimited / Free |
| MIME Type Checker | Look up the MIME type for any file extension or filename. | 100% Local | Unlimited / Free |
| Random String Generator | Generate random strings, keys and IDs to your own recipe. | 100% Local | Unlimited / Free |
| JWT Decoder & Validator | Decode, inspect, and validate JSON Web Tokens offline in your browser. | 100% Local | Unlimited / Free |
| JWT Generator | Generate custom JWT tokens using HS256, HS384, or HS512 HMAC algorithms. | 100% Local | Unlimited / Free |
| Cron Expression Generator | Build 5-part cron expressions visually with live human-readable explanations. | 100% Local | Unlimited / Free |
| Cron Expression Parser | Parse cron expressions into plain English schedules and future execution dates. | 100% Local | Unlimited / Free |
| SQL Formatter | Beautify, indent, and format SQL queries with customizable keyword casing. | 100% Local | Unlimited / Free |
| SQL Minifier | Compress SQL code by stripping comments and unnecessary whitespace. | 100% Local | Unlimited / Free |
| SQL to JSON Converter | Convert SQL INSERT statements or table queries into formatted JSON arrays. | 100% Local | Unlimited / Free |
| JSON Diff Checker | Compare two JSON objects side-by-side and highlight additions, deletions, and edits. | 100% Local | Unlimited / Free |
| YAML Formatter | Format, validate, and beautify YAML markup with syntax error checking. | 100% Local | Unlimited / Free |
| YAML to JSON Converter | Convert YAML configuration files into formatted JSON instantly. | 100% Local | Unlimited / Free |
| JSON to YAML Converter | Convert JSON payloads into clean, indented YAML configuration documents. | 100% Local | Unlimited / Free |
| TOML to JSON Converter | Convert TOML configuration files into formatted JSON objects. | 100% Local | Unlimited / Free |
| ENV File Generator | Build, format, and manage .env environment variable files with ease. | 100% Local | Unlimited / Free |