Free Online Developer Tools

All tools run entirely in your browser. No server, no uploads, no tracking. Free forever.

Why browser-based tools? Every tool on decode64.com runs entirely inside your browser tab — no file upload, no server processing, no account required. That means your data stays on your device, the tools work offline after the first load, and there are no rate limits or payload size caps. We cover the full range of everyday developer tasks: encoding and decoding (Base64, URL, HTML entities, JWT), data formatting and conversion (JSON, CSV, YAML, XML), design utilities (color picker, color palette, QR code generator), and generators (UUID, hash, regex tester).

New Tools

Base64 Encode in Linux (Command Line Guide)

How to base64 encode files and strings in Linux — terminal, command line, and scripting examples.

Live

Base64 Encode in PowerShell

How to convert and encode files to Base64 in PowerShell, with copy-paste script examples.

Live

Morse Code Translator

Convert text to Morse code and Morse code to text online.

Live

ASCII Art Generator

Generate ASCII art from text or images online for free.

Live

Binary to Text Converter

Convert binary code to readable text and text to binary online.

Live

Octal Converter

Convert between octal, decimal, hexadecimal, and binary instantly.

Live

ROT13 Encoder/Decoder

Encode and decode text with ROT13 cipher online for free.

Live

Encoding & Decoding

Encoding & Decoding

Base64 Decoder & Encoder

Decode Base64 to text or encode text to Base64. Supports files and UTF-8.

Live

Base64 Image Converter

Convert images to Base64 data URIs and decode Base64 back to images.

Live

URL Encoder & Decoder

Percent-encode URLs and decode encoded strings. Handles all special characters.

Live

HTML Entity Encoder

Encode and decode HTML entities. Convert & < > and all named/numeric entities.

Live

Decode JWT tokens. View header, payload and claims. Expiration time display.

Live

Formatters & Validators

Format, validate and beautify JSON. Syntax highlighting and error detection.

Live

JSON Minifier & Validator

Minify JSON and validate syntax. Shows size savings and exact error positions.

Live

Beautify and minify HTML code with proper indentation.

Live

Minify and format CSS. Remove comments, shorten colors, optimize zeros.

Live

Format SQL for MySQL, PostgreSQL, SQLite, SQL Server and 10 more dialects.

Live

Format, validate and convert YAML. Kubernetes, Docker, GitHub Actions config files.

Live

Design & Colors

Pick any color. Get HEX, RGB, HSL values instantly. Convert between formats.

Live

Color Palette Generator

Complementary, analogous, triadic palettes. Export CSS, SCSS, JSON, Tailwind.

Live

QR Code Generator

Generate QR codes for URLs, text, WiFi, email, SMS. Download as PNG.

Live

Converters & Generators

Epoch Converter

Convert Unix timestamps to dates. Seconds, milliseconds, ISO 8601, relative time.

Live

Generate UUID v4 in bulk. Copy, download, code examples in JS/Python/Go/SQL.

Live

MD5, SHA-1, SHA-256, SHA-512, HMAC. Hash text or files. Compare hashes.

Live

CSV to JSON Converter

Bidirectional CSV↔JSON. Auto-detect delimiter, drag & drop, RFC 4180 compliant.

Live