Stack Online Tools – Developer Utilities by stackonlinetools.com
"All-in-one productivity and developer tools with JSON formatter, text converters, password generator, SEO utilities, and more.
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About this extension
Stack Online Tools is the ultimate all-in-one productivity and developer toolkit for Firefox. Stop switching between sites or loading multiple add-ons — access 30+ essential online tools, text utilities, and developer helpers right from your browser.
Built for developers, content creators, digital marketers, SEO professionals, and everyday users, this extension speeds up workflows with fast, lightweight, and privacy-first utilities that run locally when possible.
✔ What You Get
Developer & Code Utilities
These tools make Stack Online Tools a top choice for developer tools, programmer utilities, and code formatters in Firefox.
Text & Content Utilities
Essential for writers, bloggers, SEO editors, and anyone optimizing content.
Security & Password Tools
Perfect for web developers, admins, and safe credential creation.
Image & File Tools
Quick Calculators & Generators
Key Benefits
✔ All-in-one productivity tools & utilities
✔ Fast, lightweight, and user-friendly
✔ Privacy-first — tools run locally
✔ No account, registration, or tracking
✔ Replaces multiple single-purpose add-ons
Stack Online Tools supports nearly every common workflow, from text conversions and data formatting to developer operations, making it one of the most versatile Firefox add-ons available.
Who This Is For
Built for developers, content creators, digital marketers, SEO professionals, and everyday users, this extension speeds up workflows with fast, lightweight, and privacy-first utilities that run locally when possible.
✔ What You Get
Developer & Code Utilities
- JSON Formatter & Validator – instant formatting, beautification, and error checking
- JSON ↔ YAML Converter
- Base64 Encode/Decode
- URL Encode/Decode
- HTML, CSS & JS Minifiers
- Markdown ↔ HTML Converter
- Robots.txt Generator for SEO and crawler structuring
These tools make Stack Online Tools a top choice for developer tools, programmer utilities, and code formatters in Firefox.
Text & Content Utilities
- Case Converter (uppercase, lower, title, camel, snake, kebab)
- Word & Character Counter
- URL Slug Generator
- Line Counter & List Randomizer
- Text Repeater
- Text Reverser
- Remove Duplicate Lines
Essential for writers, bloggers, SEO editors, and anyone optimizing content.
Security & Password Tools
- Strong Password Generator (custom options)
- Password Strength Checker
Perfect for web developers, admins, and safe credential creation.
Image & File Tools
- PNG ↔ JPG Converter
- PDF ↔ JPG Converter (secure web tool)
Quick Calculators & Generators
- Age Calculator
- Percentage Calculator
- Random Name Generator
- Random Address Generator
Key Benefits
✔ All-in-one productivity tools & utilities
✔ Fast, lightweight, and user-friendly
✔ Privacy-first — tools run locally
✔ No account, registration, or tracking
✔ Replaces multiple single-purpose add-ons
Stack Online Tools supports nearly every common workflow, from text conversions and data formatting to developer operations, making it one of the most versatile Firefox add-ons available.
Who This Is For
- Developers & engineers
- SEO specialists & marketers
- Writers & editors
- Designers & web admins
- Students & everyday users
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Permissions and data
Required permissions:
- Access your data for stackonlinetools.com
Data collection:
- The developer says this extension doesn't require data collection.
More information
- Add-on Links
- Version
- 1.0.2
- Size
- 127.87 KB
- Last updated
- 2 days ago (Dec 18, 2025)
- Related Categories
- License
- Mozilla Public License 2.0
- Version History
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