Resize browser window or viewport to desired screen widths.
Firefox's Responsive Design Mode (Ctrl + Shift + M) is great for mobile devices emulation.
- By:
- Moris Papasmadov
- Daily users:
- 1,026+ 28
- Rating:
- 3.23 (30)
- Version:
- 1.0.7resigned1 Last updated: 2024-04-25
- Version code:
- 5728217
- Creation date:
- 2017-06-28
- Risk:
- Very low risk impact Moderate risk likelihood
- Permissions:
- activeTab
- storage
- activeTab
- Size:
- 15.88K
- URLs:
- Privacy policy
- Source:
- Firefox Browser Add-ons
- Updated:
- a day ago
User reviews
Pros
- Resizes window width quickly and effectively as promised.
- The add-on is simple and user-friendly.
- The Ctrl+Shift+M responsive mode is appreciated and useful for testing breakpoints.
- It performs its intended function reliably with no major issues reported by some users.
Cons
- Only supports resizing window width; height resizing is missing or requested by multiple users.
- Limited number of preset widths with lack of customization options.
- Does not 'stick' to window size when sites reload, reverting to full screen.
- Keyboard shortcuts (e.g., Ctrl+Shift+M) don't work on Mac OS as expected.
- The viewport resizing affects the entire window, not just the viewport area, causing redundancy.
Recent reviews
by 天灭中共退党团队保平安, 2025-03-30
Only supports width and the "viewport" options don't resize the viewport, they resize the actual window making them redundant.
by LWGShane, 2023-03-13
Extension safety
Risk impact
Resize Window & Viewport does not require any sensitive permissions.
Risk impact analysis details
Risk likelihood
Resize Window & Viewport is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
- Good **** ********* *** **** **** *******
Upgrade to see full risk analysis details
Compare add-ons
- Compare Resize Window & Viewport vs Adjust Viewport Size
- Compare Resize Window & Viewport vs Fire Resizer
- Compare Resize Window & Viewport vs Resize Window
Similar add-ons
Here are some Firefox add-ons that are similar to Resize Window & Viewport:

Adjust Viewport Size
FullStackChoreman

Fire Resizer
Francesco De Stefano

Resize Window
79King

Window Resizer
Kelvin

Window Resize
adi291

ResizeFFWidth
Sungho Hwang

Window Resizer
antwhere.com

Viewport
Kameron

Viewport Resizer Plus
Bongvip
Popular extensions / apps
Here are some popular extensions / apps that you might be interested in:
1945 Air Force: Airplane Games
1SOFT
Ice Dodo
https://onionfist.net
Cursor Helper - Custom Cursors
https://cursor-helper.com
Email Tracker by Mailtrack®
https://mailsuite.com
Proton Pass: Free Password Manager
Proton AG
DeepL: translate and write with AI
https://deepl.com
Themes
vivo Mobile Communication Co., Ltd.
Brain Out: Can you pass it?
Focus apps
Block Blast!
HungryStudio
Opera: Private Web Browser
Opera
Google Keep - Notes and lists
Google LLC
Zomato: Food Delivery & Dining
Zomato