Firefox Browser Add-ons
  • Extensions
  • Themes
    • for Firefox
    • Dictionaries & Language Packs
    • Other Browser Sites
    • Add-ons for Android
Log in
Preview of Mobile simulator - responsive testing tool

Mobile simulator - responsive testing tool by François

Smartphone and tablet simulator on computer with several models to test mobile responsive websites.

3.9 (60 reviews)3.9 (60 reviews)
10,445 Users10,445 Users
Download Firefox and get the extension
Download file

Extension Metadata

Screenshots
About this extension
🚀 Simulate mobile viewports, check responsive web design, create impactful client demos, and save hours of testing.

Mobile FIRST is the most powerful and reliable responsive simulator extension, trusted by developers and designers for over 5 years. Our rating on the Chrome Store speaks for itself!

📱 PRE-CONFIGURED DEVICES (New ones added regularly)
• 58+ devices ready to use out of the box
• 45 smartphones (old and recent models)
• 5 tablet models
• 11 special devices (smartwatches, kiosks, desktop...)

🔥 NEW & MAIN FEATURES
• 📱📱 Multi-device comparison: View and test multiple devices side-by-side simultaneously for faster responsive checks
• 🛠️ Custom devices: Create and save your own devices with custom screen resolutions and viewports
• 👆 Realistic touch scrolling: Simulates native finger gestures for an authentic mobile browsing feel
• 🎬 One-click video capture (WEBM, GIF, MP4) for your demos and tutorials
• 📸 Transparent PNG screenshots, perfect for client emails or presentations
• 🌚 Dark mode for enhanced visual comfort

🎁 ALSO INCLUDED
• Free downloadable transparent device mockups
• Seamless landscape mode switching
• Realistic zoom mimicking actual mobile behavior
• More than 10 customization options (PWA mode, fullscreen, native keyboard, etc.)

✨ Inside Mobile FIRST, many technical tricks are integrated to reproduce the mobile experience as closely as possible.

(Note: While highly accurate for day-to-day dev, this simulator does not replace final testing on a real device for 100% full validation)
Rated 3.9 by 60 reviewers
Log in to rate this extension
There are no ratings yet

Star rating saved

5
37
4
4
3
4
2
3
1
12
Read all 60 reviews
Permissions and data

Required permissions:

  • Access browser tabs
  • Access browser activity during navigation
  • Access your data for all web sites
Learn more
More information
Add-on Links
  • Support site
  • Support Email
  • Copy add-on ID
Version
2.1.11
Size
1.03 MB
Last updated
5 years ago (15 Feb 2021)
Related Categories
  • Web Development
Licence
All Rights Reserved
Version History
  • See all versions
Add to collection
Report this add-on
Go to Mozilla's homepage

Add-ons

  • About
  • Firefox Add-ons Blog
  • Extension Workshop
  • Developer Hub
  • Developer Policies
  • Community Blog
  • Forum
  • Report a bug
  • Review Guide

Download

  • Download Firefox
  • Windows
  • macOS
  • iOS
  • Android
  • Linux
  • All

Latest Builds

  • Nightly
  • Beta

Firefox for Business

  • Enterprise

Community

  • Connect
  • Contribute
  • Developer

Follow

  • Instagram
  • YouTube
  • TikTok
  • Bluesky
  • Podcast
  • Privacy
  • Cookies
  • Legal

Except where otherwise noted, content on this site is licensed under the Creative Commons Attribution Share-Alike Licence v3.0 or any later version.