---
title: "Responsive Tester - Mobile View, Breakpoint Checker & CSS Editor – Chrome extension stats, history and permissions"
description: "53 users, no ratings yet. Version 1.9.0, updated 2026-09-15. Requests 7 permissions."
url: "https://extensiontracker.com/extension/ekefkjaknejhmepccobnpdedfdkjcali"
---

# Responsive Tester - Mobile View, Breakpoint Checker & CSS Editor

Live in the Chrome Web Store.

- Users: 53
- Rating: no ratings yet
- Last checked: 2026-09-27 00:35 UTC
- Users gained in 7 days: – (needs a week of history)
- Users gained in 30 days: – (needs a month of history)
- Rank by users: #83,109 of 264,702 live extensions
- Rank in Developer Tools: #7,783 of 27,615

## The listing

What the Chrome Web Store shows, as of the last check.

Summary from the listing:

> Preview any page on multiple screens at once. Test mobile view, every screen size and breakpoint, and edit CSS live.

- Extension ID: `ekefkjaknejhmepccobnpdedfdkjcali`
- Developer: [Mr Violets](https://extensiontracker.com/developer/ub35186ba2fe065983d099b234cc90e37)
- Category: [Productivity › Developer Tools](https://extensiontracker.com/category/productivity/developer)
- First published: 2026-07-13
- Last updated: 2026-09-15
- Version: `1.9.0`
- Size: 303 KiB
- Minimum Chrome: 116
- Languages (10): Deutsch, English, Tiếng Việt, español, français, português (Brasil), português (Portugal), русский, हिन्दी, 日本語
- Website: `responsive-tester.app`
- Chrome Web Store: <https://chromewebstore.google.com/detail/responsive-tester-mobile/ekefkjaknejhmepccobnpdedfdkjcali>
- View the code or download the CRX, in CRX Peek: <https://crxpeek.com/?id=ekefkjaknejhmepccobnpdedfdkjcali>

## Users over time

One row per check, newest first, as shown on the Chrome Web Store.

| Checked | Users | Rating | Ratings |
| --- | ---: | ---: | ---: |
| 2026-09-27 | 53 | – | – |

## What changed

Every change found on a check, newest first.

No changes found since tracking began on 2026-09-27.

## What it can access

From the extension's manifest, in plain language.

**Every website:** it can read and change your data on all the sites you visit.

### Sites

- `<all_urls>`: Every website

### Browser features

- `contextMenus`: Add items to the right-click menu
- `declarativeNetRequestWithHostAccess`: Block or change network requests on the sites it can reach
- `offscreen`: Open a hidden page for background work
- `scripting`: Run scripts on sites it can reach
- `storage`: Save settings and data in your browser
- `webNavigation`: Follow your browsing, page by page

### Asked for later, if you agree

- `clipboardWrite`: Change what's in your clipboard

## More from this developer

Other extensions from the same publisher account.

| Extension | Users | Rating | Ratings | Category |
| --- | ---: | ---: | ---: | --- |
| [Screen Ruler - Measure and Inspect the Web](https://extensiontracker.com/extension/jfbbgijjljfbolelfkopkhbfjajjampm) | 60,000 | 4.29 | 62 | Developer Tools |
| [Stay Awake: Keep Your Computer Awake](https://extensiontracker.com/extension/gofaiibillcpfajafckhoieamembimje) | 10,000 | 4.67 | 3 | Workflow & Planning |
| [UI Inspector - Visual CSS Editor](https://extensiontracker.com/extension/dadpnbadaicglhbgoboopllcbemfipoo) | 5,000 | 4.00 | 21 | Developer Tools |
| [Marble: Automatically Organized Tab Groups](https://extensiontracker.com/extension/faadmipaelbkbdfjkfpiiomoplihjhdm) | 2,000 | 4.50 | 26 | Workflow & Planning |
| [Deep Tab Search: Tab Switcher & Search](https://extensiontracker.com/extension/dbppkkjmaloclihjakcpnionomlidbhk) | 945 | 3.25 | 12 | Workflow & Planning |
| [Quilt - Tiling Window Manager](https://extensiontracker.com/extension/ikjaecdfcaoegkfgjhhkjgcpmackbnki) | 794 | 5.00 | 3 | Workflow & Planning |
| [CSS Viewer - Inspect & Copy Any Element's CSS](https://extensiontracker.com/extension/bbiflmjfnokkgbppcenonccmfkhoaehb) | 470 | – | – | Developer Tools |
| [Pointer - Element Inspector for DevTools](https://extensiontracker.com/extension/keomkegfndepkhgeeediaeemebnnjafc) | 199 | 3.00 | 2 | Developer Tools |
| [AltCue - Tab Switcher](https://extensiontracker.com/extension/kdlbchidplmkbcihfjgambelnaaaienc) | – | 1.00 | 1 | Functionality & UI |

All 10 extensions by [Mr Violets](https://extensiontracker.com/developer/ub35186ba2fe065983d099b234cc90e37).

## About this data

Collected from the extension's public Chrome Web Store listing. It's checked every month, and again whenever a new version appears. Last checked 2026-09-27 00:35 UTC; next check around 2026-10-25.

How the data is collected: <https://extensiontracker.com/methodology>.

## Cite this page

Extension Tracker. “Responsive Tester - Mobile View, Breakpoint Checker & CSS Editor” (ekefkjaknejhmepccobnpdedfdkjcali). Chrome Web Store data, last checked 2026-09-27. https://extensiontracker.com/extension/ekefkjaknejhmepccobnpdedfdkjcali. Accessed 2026-09-28.

```bibtex
@misc{extensiontracker_ekefkjaknejhmepccobnpdedfdkjcali,
  title   = {Responsive Tester - Mobile View, Breakpoint Checker & CSS Editor (ekefkjaknejhmepccobnpdedfdkjcali)},
  author  = {{Extension Tracker}},
  year    = {2026},
  note    = {Chrome Web Store data, last checked 2026-09-27},
  url     = {https://extensiontracker.com/extension/ekefkjaknejhmepccobnpdedfdkjcali},
  urldate = {2026-09-28}
}
```

---

From Extension Tracker, a public record of the Chrome Web Store: <https://extensiontracker.com/extension/ekefkjaknejhmepccobnpdedfdkjcali>. It isn't affiliated with Google. The data is free to reuse under CC BY 4.0 (<https://creativecommons.org/licenses/by/4.0/>), crediting Extension Tracker. Extension, developer and list pages come as Markdown too: add `format=md` to the address, as in `https://extensiontracker.com/extension/{id}?format=md`.