✨100+ Free Online Tools
All Online Tools in One Box
No need to bookmark tools separately. Stack Online Tools is your free all-in-one solution for text, code, SEO, and more.
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Browse by Category
Explore our comprehensive collection of online tools organized by category for easy access.
Text Tools
Transform, analyze, and manipulate text
10tools
String & List Utilities
Manipulate lists, strings, and data structures
3tools
Encoding & Decoding
Encode, decode, and hash data
4tools
JSON & Data
Format, convert, and validate data
7tools
Code & Developer
Format, minify, and test code
8tools
SEO & Marketing
Optimize content for search engines
5tools
Markdown
Edit and convert Markdown
5tools
Image Tools
Process and convert images
2tools
PDF Tools
Manipulate PDF documents
2tools
Math & Calculation
Calculate and convert units
2tools
Privacy & Security
Generate passwords and secure data
2tools
Miscellaneous
Other useful utilities
2tools
Text Tools
Transform, analyze, and manipulate text
Case Converter
Convert text between uppercase, lowercase, title case, sentence case, camelCase, snake_case, and more
Word Counter
Count words, characters, sentences, paragraphs, and reading time with readability scores
Text Repeater
Repeat input text a set number of times with custom separators
Text Reverser
Reverse text characters, flip text upside down, or reverse word order with one click
Remove Line Breaks
Remove all line breaks from text while preserving other formatting and spacing
Remove Extra Spaces
Remove extra spaces and tabs from text to clean up formatting and improve readability
String & List Utilities
Manipulate lists, strings, and data structures
Encoding & Decoding
Encode, decode, and hash data securely
Base64 Encoder/Decoder
Encode and decode Base64 strings with support for images and files
HTML Entity Encoder
Encode HTML into entities using named or numeric references with decimal or hex.
HTML Entity Decoder
Decode HTML entities back to plain text characters instantly.
URL Encoder/Decoder
Encode and decode URL strings with percent-encoding. Auto conversion with option to escape all characters.
JSON & Data Tools
Format, convert, and validate data
JSON Formatter
Format, validate, and beautify JSON with syntax highlighting
JSON to YAML Converter
Convert JSON to YAML with instant transformation and export options.
YAML to JSON Converter
Convert YAML to JSON with instant transformation and syntax validation.
JSON to XML Converter
Convert JSON to XML with instant transformation, proper escaping, and export options.
XML to JSON Converter
Convert XML to JSON with instant transformation, attribute handling, and export options.
JSON to CSV Converter
Convert JSON data to CSV format with custom delimiters
Code & Developer Tools
Format, minify, and test code
Diff Checker
Compare two texts and highlight differences with side-by-side view, statistics, and export options
JavaScript Obfuscator
Obfuscate JavaScript code to protect intellectual property with advanced protection options
JavaScript Validator
Validate JavaScript code for syntax errors and common issues with real-time feedback
JavaScript Minifier
Minify JavaScript by removing comments and whitespace. Upload, copy, and download supported.
CSS Validator
Validate CSS code with W3C standards, check syntax errors, and ensure compliance with CSS profiles
CSS Minifier
Minify CSS by removing comments and unnecessary whitespace. Upload, copy, and download supported.
SEO & Marketing Tools
Optimize content for search engines
URL Slug Generator
Generate RFC 3986-compliant, SEO-friendly URL slugs from text lines
Open Graph Checker
Fetch a page and inspect its Open Graph and Twitter meta tags with live previews.
Page Title & Meta Description Length
Measure title and meta description character and pixel lengths with live Google SERP preview.
Robots.txt Generator
Generate a clean robots.txt file with user-agent, disallow/allow rules, crawl delay, and sitemap support.
Google SERP Simulator
Preview how your page appears on Google with editable title, description, URL, and site name. Toggle Desktop and Mobile views and fetch metadata from a URL.
Frequently Asked Questions
Absolutely! All our tools are completely free to use. We believe in providing valuable utilities without any cost barriers. You can use any tool as many times as you need without restrictions.
We maintain our free service through minimal, non-intrusive advertising and optional premium features. Our core mission is to provide free access to essential online tools for everyone.
No account required! You can use all our tools immediately without signing up. However, creating a free account allows you to save your work, access history, and enjoy additional features.
Yes, we take privacy seriously. All data processing happens in your browser when possible. For server-side processing, we use secure connections and don't store your data longer than necessary.
Absolutely! We love hearing from our users. You can suggest new tools through our Suggest a Tool section. We regularly add new utilities based on user feedback and needs
Our tools work on all modern browsers including Chrome, Firefox, Safari, and Edge. We recommend using the latest version of your preferred browser for the best experience.
Yes, you can use our tools for both personal and commercial purposes. We only ask that you don't resell or redistribute our tools as your own product.
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