Developer Tools

Developer Tools

JSON, encoding, formatting, validation, and code utilities for developers.

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15 tools in Developer Tools

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JSON Formatter & Beautifier

Format, prettify, and validate JSON instantly in your browser.
Browser

JSON Validator

Validate JSON syntax and structure. Get clear error messages.
Browser

JSON Diff Checker

Compare two JSON objects and see what changed.
Browser

Base64 Encoder

Encode text or files to Base64 format instantly.
Browser

Base64 Decoder

Decode Base64 strings back to text or binary.
Browser

URL Encoder

Percent-encode text for safe use in URLs and query strings.
Browser

URL Decoder

Decode percent-encoded URL strings back to readable text.
Browser

HTML Escape

Escape special HTML characters to prevent injection.
Browser

HTML Unescape

Convert HTML entities back to their original characters.
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Regex Tester

Test and debug regular expressions with live match highlighting.
Browser

Text Diff Checker

Compare two text blocks and highlight what changed.
Browser

Text Case Converter

Convert text between UPPERCASE, lowercase, Title Case, camelCase, and more.
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Word Counter

Count words, characters, lines, and reading time.
Browser

Markdown Preview

Write Markdown and preview the rendered HTML in real-time.
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UUID Generator

Generate one or many UUIDs (v4) instantly.

Free online tools built for developers

Developer tools on it.you cover the everyday tasks that come up constantly when building, debugging, and maintaining software: formatting messy JSON from an API response, encoding a string to Base64 for an Authorization header, testing a regex against sample log data, generating a UUID for a new record, or comparing two config files to find what changed.

Every tool runs entirely in your browser using JavaScript — no data is uploaded to any server. That matters when you're working with credentials, API keys, or customer data you can't paste into an unknown third-party website. Format JSON from a production database, hash a password, or decode a JWT — it all stays on your machine.

Who uses these tools?

Backend developers
Format API responses, validate JSON schemas, decode JWTs, and generate UUIDs without leaving the browser.
Frontend engineers
Encode images to Base64 data URIs, escape HTML for safe rendering, test regex patterns against user input.
DevOps & sysadmins
Compare config file diffs, format YAML, convert timestamps, and minify scripts for deployment.
Students & learners
Explore encoding formats, understand regular expressions, and practice with real output.

What's in this category?

JSON Formatter & Beautifier
Format, prettify, and validate JSON instantly in your b
JSON Validator
Validate JSON syntax and structure. Get clear error mes
JSON Diff Checker
Compare two JSON objects and see what changed.
Base64 Encoder
Encode text or files to Base64 format instantly.
Base64 Decoder
Decode Base64 strings back to text or binary.
URL Encoder
Percent-encode text for safe use in URLs and query stri

Tool types in this category

Type Count How it works Privacy
Browser-only 15 Runs entirely in your browser — no server requests No data leaves your device

Key concepts

JSON — JavaScript Object Notation — the de facto data exchange format for APIs. Must be valid UTF-8 with strictly double-quoted keys.
Base64 — A binary-to-text encoding that represents binary data using 64 printable ASCII characters. Used in HTTP Auth headers, data URIs, and email attachments.
Regular expressions — A pattern-matching language for searching, validating, and extracting text. Supported natively in JavaScript, Python, Go, and most modern languages.
UUID v4 — A 128-bit randomly generated identifier. Near-zero collision probability makes it suitable for distributed primary keys without a central coordinator.
Text diff — An algorithm (typically Myers or patience diff) that finds the minimum edit distance between two text sequences, showing added, removed, and unchanged lines.
Hash functions — One-way mathematical functions that map data of any size to a fixed-length digest. Used for data integrity checks, password storage, and digital signatures.

Frequently asked questions

Is my data safe when I use these tools?
Yes. All developer tools on it.you run entirely in your browser using JavaScript. No data is sent to any server. You can use them safely with sensitive data including API keys, credentials, and production database output.
What is the difference between JSON formatting and JSON validation?
Formatting (prettifying) takes valid JSON and adds indentation and line breaks for readability. Validation checks whether the JSON is syntactically correct — it will report the exact line and character where an error occurs.
When should I use Base64 encoding?
Use Base64 when you need to embed binary data (images, files) in text-based formats like HTML, CSS, or JSON. Also used in HTTP Basic Auth headers (username:password) and JWT tokens.
What is the difference between MD5, SHA-1, and SHA-256?
All three are hash functions, but they differ in output size and security. MD5 (128-bit) and SHA-1 (160-bit) are cryptographically broken — do not use them for security. SHA-256 (256-bit, part of SHA-2) is the current standard for integrity checks and digital signatures.
What does a UUID v4 look like?
A UUID v4 looks like: 550e8400-e29b-41d4-a716-446655440000. It's 32 hexadecimal digits split into 5 groups by hyphens. The "4" in the third group indicates version 4 (random).

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