Free Online Developer Tools
Free online developer tools — JSON formatter, Base64 encoder, QR code generator, timestamp converter, and more. No sign-up required.
20 tools · 100% client-side · No sign-up · Works on any device
Popular Tools
JSON Formatter
Format, validate, and beautify JSON data instantly. Parse and fix malformed JSON with syntax highlighting.
QR Code Generator
Generate QR codes from URLs, text, or any data. Customizable size and color. Free, no sign-up needed.
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 strings back to plain text. Supports UTF-8 and binary data.
Password Generator
Generate strong, secure passwords with customizable length, symbols, numbers, and case options.
Image Compressor
Compress JPEG, PNG, and WebP images online. Reduce file size without losing quality. 100% client-side.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text input.
Developer Tools
View all →JSON Formatter
Format, validate, and beautify JSON data instantly. Parse and fix malformed JSON with syntax highlighting.
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 strings back to plain text. Supports UTF-8 and binary data.
URL Encoder / Decoder
Encode special characters for URLs or decode percent-encoded URLs back to readable text.
Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds.
Markdown Previewer
Write and preview Markdown in real-time. See how your Markdown renders as HTML instantly.
Regex Tester
Test regular expressions against text with real-time matching. See matches, groups, and replacements.
UUID Generator
Generate random UUIDs (v4) and GUIDs. Copy with one click. Perfect for developer testing.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text input.
JWT Decoder
Decode JWT tokens and inspect the header, payload, and signature. No data is sent to any server.
HTML Entity Encoder / Decoder
Encode special HTML characters to entities and decode HTML entities back to readable text.
Text Diff Checker
Compare two texts and find differences instantly. See what was added, removed, or changed line by line.
Text Tools
View all →Word Counter
Count words, characters, sentences, and paragraphs. Get reading time estimates for your text.
Lorem Ipsum Generator
Generate Lorem Ipsum placeholder text for your designs. Customize paragraph count and length.
Text Deduplicator
Remove duplicate lines from text. Sort alphabetically, keep first occurrence, or remove all duplicates.
Case Converter
Convert text to uppercase, lowercase, title case, sentence case, camelCase, snake_case, and more.
Image Tools
View all →Utility Tools
View all →QR Code Generator
Generate QR codes from URLs, text, or any data. Customizable size and color. Free, no sign-up needed.
Password Generator
Generate strong, secure passwords with customizable length, symbols, numbers, and case options.
Color Converter
Convert colors between HEX, RGB, HSL, and HSV formats. Pick colors visually with the color picker.
Why Use DevToolsBox?
Every tool runs entirely in your browser. Your data never leaves your device, which keeps sensitive input completely private.
All 20 tools are completely free with no registration, no usage caps, and no premium tiers. Just open and use.
Static pages with minimal JavaScript load instantly. No heavy frameworks, no tracking bloat, no waiting.
Runs on any modern browser on desktop, tablet, or phone. Nothing to install or update.
Frequently Asked Questions
Are these tools really free?
Yes. Every tool on DevToolsBox is completely free with no sign-up, no account, and no usage limits. There are no premium tiers or hidden paywalls — the entire toolbox is available to everyone.
Is my data safe? Do you upload what I type?
Your data never leaves your browser. All tools run entirely client-side using JavaScript, so anything you paste or upload is processed locally on your device and is never transmitted to or stored on any server.
Do these tools work offline?
Once a tool page has loaded, the processing runs in your browser, so it will keep working even if you lose your internet connection. An initial connection is only needed to load the page itself.
Which browsers and devices are supported?
DevToolsBox works on any modern browser — Chrome, Firefox, Safari, Edge — on desktop, tablet, and mobile. There is nothing to install; just open the tool page in your browser.
Can I use these tools for commercial work?
Yes. You are free to use the tools for personal or commercial projects. The output they produce is yours to use however you like.