Free Online Developer Tools

Essential utilities for developers — JSON formatting, Base64 encoding, hash generation, regex testing, JWT decoding, UUID generation, and much more. Everything runs locally in your browser. No server, no data leaks, no sign-up.

Runs in your browser20+ toolsFree forever

Encoding & Decoding

Encode and decode Base64 strings, images, and binary data.

Base64 Encoder

Encode text to Base64

Use tool →Base64 Decoder

Decode Base64 strings

Use tool →Image to Base64

Convert images to Base64 strings

Use tool →Base64 to Image

Convert Base64 strings to images

Use tool →

Format & Transform

Format, validate, and transform data between representations.

Timestamp Converter

Convert Unix timestamps to dates

Use tool →String Escaper

Escape strings for various formats

Use tool →JSON Formatter

Format and beautify JSON data

Use tool →ASCII Converter

Convert text to ASCII codes

Use tool →Bulk File Renamer

Rename multiple files with patterns

Use tool →Code Minifier

Minify CSS, JavaScript, and HTML

Use tool →

Analyze & Inspect

Decode, test, and understand tokens, expressions, and syntax.

JWT Decoder

Decode and inspect JWT tokens

Use tool →Regex Tester

Test and debug regular expressions

Use tool →Cron Expression Explainer

Understand and test cron expressions

Use tool →JSON Viewer

View and explore JSON data

Use tool →

Generate & Create

Create tokens, hashes, UUIDs, commands, and other assets.

JWT Generator

Generate JWT tokens

Use tool →cURL Command Builder

Build and test cURL commands

Use tool →Bcrypt Hash Generator

Generate and verify bcrypt hashes

Use tool →Favicon Generator

Generate favicons from images

Use tool →UUID Generator

Generate random UUIDs/GUIDs

Use tool →Hash Generator

Generate MD5, SHA-1, SHA-256 hashes

Use tool →

Color & Design

Pick colors, build gradients, and extract palettes from images.

CSS Gradient Generator

Create CSS gradients visually

Use tool →Color Palette Generator

Generate color palettes from images

Use tool →Image Color Picker

Pick colors from images

Use tool →

Why Use FlexKit Developer Tools?

Your data never leaves your machine

All operations run in your browser — no API calls, no telemetry, no logs. Paste sensitive tokens or data without worry.

Fast and always available

No backend to go down. Tools load instantly and work offline after the first visit.

No account or installation needed

Bookmark a URL and use the tool immediately — nothing to install, no email required.

Purpose-built for developer workflows

Each tool is designed around real tasks: debugging JWTs, formatting API responses, building cURL commands, and more.

Frequently Asked Questions

Is it safe to paste JWT tokens or passwords here?

Yes. All processing happens locally in your browser using JavaScript. Nothing is transmitted to a server — your sensitive data stays on your device.

Which hash algorithms are supported?

The Hash Generator supports MD5, SHA-1, SHA-256, and SHA-512. The Bcrypt Generator supports bcrypt hashing and verification.

Can I use these tools offline?

After the initial page load, most tools work without an internet connection since all logic runs client-side.

How do I decode a JWT token?

Use the JWT Decoder tool — paste your token and it instantly displays the header, payload, and expiration information without requiring the signing secret.