DevBox

Free Developer Tools Online

Format JSON, test regex, encode Base64 and URLs, and generate passwords, UUIDs and hashes free online — in your browser.

Base64 Encoder & Decoder

Encode and decode Base64 free online

Hash Generator

Generate MD5, SHA-1, SHA-256 and SHA-512 hashes online free

HTML / CSS / JS Minifier

Minify HTML, CSS and JavaScript free online with Terser

JSON Formatter & Validator

Format, minify and validate JSON free online

Password Generator

Generate strong random passwords free online

QR Code Generator

Generate custom QR codes free in your browser

Regex Tester

Test regular expressions free online

URL Encoder & Decoder

Encode and decode URLs free online

UUID Generator

Generate free UUID v4 (GUID) identifiers online in bulk

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AI Regex Generator

Describe the pattern, get a working regular expression

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AI Code Explainer

Plain-English explanations of any code snippet

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HTML Entity Encoder

Encode HTML special characters safely.

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HTML Entity Decoder

Decode HTML character references into plain text.

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Text to Unicode Escapes

Convert text to JavaScript Unicode escapes.

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Unicode Escape Decoder

Decode Unicode escape sequences into characters.

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JSON to CSV

Convert a JSON array of flat records into a correctly quoted CSV.

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CSV to JSON

Parse quoted CSV rows into JSON records.

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JSON Key Sorter

Sort object keys recursively without changing array order.

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JSON Pretty Printer

Indent valid JSON for easier reading.

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JSON String Escaper

Create a safe JSON string literal from arbitrary text.

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XML Formatter

Validate and indent an XML document locally.

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HTML Text Extractor

Extract readable plain text from pasted HTML.

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Unix Timestamp to Date

Convert a Unix timestamp to UTC ISO date/time.

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ISO Date to Unix Timestamp

Convert an ISO date/time to seconds and milliseconds since the epoch.

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AI User Story Generator

Create a reviewed draft using your chosen AI provider.

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AI Acceptance Criteria Writer

Create a reviewed draft using your chosen AI provider.

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AI Test Case Generator

Create a reviewed draft using your chosen AI provider.

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AI Commit Message Writer

Create a reviewed draft using your chosen AI provider.

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AI README Generator

Create a reviewed draft using your chosen AI provider.

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AI SQL Query Explainer

Create a reviewed draft using your chosen AI provider.

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AI Code Review Assistant

Create a reviewed draft using your chosen AI provider.

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AI CSS Explainer

Create a reviewed draft using your chosen AI provider.

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JWT Decoder & Inspector

Decode header/payload locally without treating it as verified

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JSON to TypeScript Types

Generate TypeScript interfaces from example JSON

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JSON Schema Generator

Generate JSON Schema from representative objects

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JSON Schema Validator

Validate JSON files against provided schema

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HTML Beautifier

Reformat pasted HTML consistently

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CSS Beautifier

Pretty-print or re-indent CSS

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JavaScript Beautifier

Reformat JavaScript for review without executing it

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SQL Formatter

Format SQL queries and highlight statements

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SQL to JSON Data Mapper

Transform exported SQL rows into JSON safely

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Cron Expression Builder

Generate cron schedules and show next run times

Planned tool Coming SoonDevBox

Cron Expression Explainer

Translate cron notation into plain language

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URL Parser

Inspect query parameters, hostname, port and fragments

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CSS Clamp Generator

Generate fluid CSS clamp values from screen limits

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Flexbox Playground

Interactively adjust CSS flexbox layouts

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CSS Grid Playground

Interactively adjust grid tracks and alignment

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HTTP Status Code Lookup

Explain status codes with examples

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HTTP Request Builder

Compose cURL/fetch snippets without sending secrets

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CSP Header Builder

Create restrictive Content-Security-Policy header rules

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Regex Replace Preview

Apply matched replacements with safe previews

32 available tools. Read each tool’s inputs and processing details before starting.

Frequently asked questions

Are these developer tools really free?

Yes — every tool on this page is completely free.

Is the password generator cryptographically secure?

Yes — it uses your browser’s crypto.getRandomValues(), the same secure random source behind the Web Crypto API.

Which regex flavor does the tester use?

JavaScript (ECMAScript) regular expressions — the same engine your browser and Node.js use.

Is my code or data uploaded?

No. Everything is processed locally in your browser; nothing leaves your device.

Do the tools work offline?

Once the page has loaded, the pure-JavaScript tools keep working without a network connection.