Viewport Resizer: Ultimate Device Emulator & Website Testing Tool icon

Viewport Resizer: Ultimate Device Emulator & Website Testing Tool

by Malte Wassermann · Developer Tools
FeaturedManifest V3 Free
View in Chrome Web Store Data as of 15 Oct 2026

Emulate devices, resize screens, and perfect your web design effortlessly with this cutting-edge testing and presentation tool.

Users
80K
0 in 30 days
Rating
4.1 / 5
−0.14 in 30 days
Ratings
286
+1 in 30 days
Store rank
#2,571
#2,256 among extensions
Version
2.0.4
updated 16 Dec 2025

Users

monthly, 3 years
20K55K90KAug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 80,000 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 years
80183286Aug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 286 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Viewport Resizer: Ultimate Device Emulator & Website Testing Tool

Enhance your web design experience with our dynamic testing and presentation tool, designed to create, test, and showcase your digital experiences on any device, from wearables to very big screens. Customize your workspace fully and use or create your own device mockups, explore various display resolutions, and harness advanced emulation features like touch fingerprint simulation, user-agent emulation, and breakpoint guide, all within a professional-grade environment built for high-quality development and debugging. Push your limits with an intuitive zoomable workspace, precise ruler and grid tools, and a sleek presentation mode called 'Coffee Mode' — think of this tool as a first-level approximation of how your digital experience looks and feels across multiple devices. Limitations: While our tool provides comprehensive device simulations, it does not replace the need for physical device testing.

Growth

WindowUsersChangeRatingsRating
7 days0+0.0%0−0.14
30 days0+0.0%+1−0.14
6 months0+0.0%+1−0.14
1 year0+0.0%+3−0.15

Chrome Web Store search rankings

Where Viewport Resizer: Ultimate Device Emulator & Website Testing Tool appears when people search the store, with the 30 day change
Search phrasePosition30 days
device#9+2
tool#20+15
testing#29−7
website#85−1

Version history

6 versions recorded
2.0.416 Dec 2025
2.0.319 Nov 2024
2.0.220 Jun 2024
2.0.114 Jun 2024
1.2.13 Jun 2024
1.1.928 Dec 2019

Details

Category
Developer Tools
First seen
28 Dec 2019
Size
134 KB
Languages
de, en, id, nl, vi, tr, ca, da
Pricing
Free
Extension ID
kapnjjcfcncngkadhpmijlkblpibdcgm

Permissions and risk

Minimal riskimpact 2, likelihood 0
Permissions
activeTabscriptingdeclarativeNetRequeststorage
Site access
<all_urls>
Can read and change data on every website you visit.

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