Free Online Developer Tools

Fast, privacy-friendly utilities for encoding, hashing, formatting, and more. Everything runs in your browser — nothing is sent to a server.

Meta Tag Validator

Validate and score your website's meta tags for SEO. Check Open Graph, Twitter Cards, and more.

Encoding

Base64 Encode/Decode

Encode text to Base64 or decode Base64 to text instantly.

URL Encode/Decode

Percent-encode or decode URLs and query parameters.

JWT Decoder

Decode and inspect JSON Web Tokens without sending them to a server.

HTML Entity Encoder/Decoder

Encode special characters to HTML entities or decode them back.

Crypto

Hash Generator

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text.

TOTP Code Generator

Generate time-based one-time passwords from a secret key for debugging 2FA flows.

OTP QR Code Decoder

Decode OTP QR codes to inspect otpauth:// URI parameters like issuer, secret, and algorithm.

Generators

UUID Generator

Generate random UUIDs (v4) in bulk with one click.

Lorem Ipsum Generator

Generate placeholder text in paragraphs, sentences, or words.

Mock Data Generator

Generate realistic fake data for testing. Customizable fields, JSON or CSV output.

Converters

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates.

Color Converter

Convert colors between HEX, RGB, HSL, and HSV formats.

Formatters

JSON Formatter & Validator

Format, validate, and minify JSON with syntax highlighting.

Text

Text Diff Checker

Compare two blocks of text and see the differences highlighted.

Regex Tester

Test regular expressions against text with real-time match highlighting.

What is ToolPane?

ToolPane is a collection of free, fast developer tools that run entirely in your browser. From Base64 encoding and JWT decoding to JSON formatting and regex testing — every tool processes your data client-side using JavaScript APIs like Web Crypto, TextEncoder, and the DOM. No server requests, no data storage, no accounts required.

Why Use Browser-Based Developer Tools?

Traditional online tools send your data to a server for processing. ToolPane is different — all computation happens locally in your browser. This means your API keys, tokens, passwords, and sensitive data never leave your device. It also means instant results with no network latency, and the tools work offline once loaded.

Privacy-First, No Sign-Up Required

ToolPane requires no account, no login, and no personal information. There are no usage limits, no premium tiers, and no data collection beyond basic anonymous analytics. Every tool is completely free and always will be. We believe developer utilities should be fast, private, and accessible to everyone.