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Data Stays on Your Device

Privacy-First
Developer Tools

Lightning-fast utilities that work 100% locally in your browser. No signup. No data collection. Just pure productivity.

32+ Tools
100% Free
No Signup
32 tools
Popular:PDFPDFSVGSEOJSONJSONBase64HTMLQRYAMLJSONText

100% Private

All processing happens locally in your browser. Your data never leaves your device.

Lightning Fast

Instant results with no server delays. Process large files at maximum speed.

Always Free

No hidden fees, no premium tiers. All tools are completely free forever.

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Converters

8
PDF Compressor
Compress PDF file sizes locally in your browser with quality controls and live reduction metrics.
PDF Merger & Splitter
Combine multiple PDF files into one or extract specific page ranges securely.
Timestamp Converter
Convert between Unix timestamps and human-readable dates
Image Compressor
Compress images to reduce file size without losing quality.
Image Converter
Convert images between formats (JPG, PNG, WebP, etc).
YAML ↔ JSON Converter
Convert between YAML and JSON formats instantly. Paste your data and switch formats for easy integration.
JSON ↔ TOON Converter
Convert between JSON and TOON (Token-Oriented Object Notation) to reduce token count for transmission and LLM usage.
String Case Converter
Convert text between camelCase, snake_case, kebab-case, PascalCase, and detailed title case.

Design

4
SVG Wave & Blob Generator
Generate customizable SVG waves, section dividers, and organic blobs for web design.
CSS Glassmorphism Studio
Create modern frosted glass UI effects, shadows, and backdrop blurs with ready-to-copy CSS.
Color Picker
Pick colors and convert between HEX, RGB, HSL formats
Gradient Maker
Create beautiful CSS gradients and copy the code.

Generators

8
SEO Meta & OpenGraph Generator
Generate complete HTML meta tags for Google SEO, Twitter cards, and Facebook previews.
Password Generator
Generate secure passwords with customizable options
Hash Generator
Generate MD5, SHA1, SHA256 hashes from text
UUID Generator
Generate unique identifiers (UUID v1, v4)
JSON Generator
Generate random JSON objects for testing and development.
Paragraph Generator
Generate random placeholder paragraphs for testing and design.
QR Code Generator
Generate QR codes for URLs, text, or any data. Download and share instantly.
Chmod Calculator
Calculate Linux file permissions (e.g., 777, 755) using checkboxes or numeric input.

Formatters

5
JSON Formatter
Format, validate, and beautify JSON data with syntax highlighting and error detection
JSON Beautifier
Beautify and fix broken JSON by adding missing quotes to keys and string values.
HTML Formatter
Format and beautify HTML code with proper indentation and syntax highlighting
CSS Minifier
Minify CSS code to reduce file size
SQL Formatter
Format and beautify complex SQL queries for better readability.

Encoders

3
Base64 Encoder/Decoder
Encode and decode Base64 strings instantly with download support
URL Encoder/Decoder
Encode and decode URLs for safe transmission
JWT Decoder
Decode and inspect JWT tokens. View header and payload.

Validators

2
JSON Validator
Validate JSON against schemas with error highlighting and schema generation
JSON Compare
Find differences between two JSON objects.

Testing

2
Regex Tester
Test and debug regular expressions with real-time matching
Text Diff Checker
Compare two texts or code snippets to find differences (lines added, removed, or modified).

Frequently Asked Questions & User Guide

Learn more about uToolsLib, our commitment to developer privacy, and how to get the most out of our free web utilities.

How does uToolsLib protect my privacy?

Unlike traditional online utility websites that transmit your data to backend servers for processing, uToolsLib runs 100% locally in your browser using JavaScript. Your database queries, JSON files, API secrets, or passwords never leave your computer. This client-side processing design makes it secure even for enterprise configurations and confidential data checks.

Is there any limit or sign-up requirement?

No. We believe developer tools should be friction-free. You do not need to create an account, register, log in, or pay for premium licenses. All tools, from our high-performance SQL Formatter to the Image Compressor and UUID Generator, are fully open and free for personal, educational, and commercial purposes.

Can I use uToolsLib offline?

Yes. Once you initially load uToolsLib, the files are cached by your browser. Because the processing logic (JSON validation, Base64 encoding, formatting) is written entirely in client-side code, most tools will continue to work perfectly even if you disconnect from the internet.

What types of utilities are available?

uToolsLib provides utility categories covering everyday programming workflows:
  • Formatters: Beautifiers for JSON, HTML, SQL, and CSS files.
  • Converters: Instantly transform YAML to JSON, change String Cases, or parse Unix Timestamps.
  • Generators: Generate secure passwords, random JSON datasets, unique UUID vectors, or QR codes.
  • Encoders: Encode and decode Base64 strings, URL components, and inspect JWT tokens.

Need a Custom Tool or Found a Bug?

We are constantly refining our codebase and adding new developer utility tools to our index. If you have recommendations, security questions, or feedback, feel free to get in touch.

Contact Support