---
title: "Core Web Vitals Visualizer – Chrome extension stats, history and permissions"
description: "10,000 users, rated 4.95 by 19 people. Version 1.22, updated 2026-10-10. Requests 1 permission."
url: "https://extensiontracker.com/extension/mcffmgagphgpgkdclllnilokablhjcge"
---

# Core Web Vitals Visualizer

Live in the Chrome Web Store.

- Users: 10,000
- Rating: 4.95 from 19 ratings
- Last checked: 2026-11-09 06:02 UTC
- Users gained in 7 days: No change
- Users gained in 30 days: No change (+0.0%)
- Rank by users: #5,041 of 292,131 live extensions
- Rank in Developer Tools: #442 of 30,442

## The listing

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

Summary from the listing:

> Measure, visualize, and debug Core Web Vitals in real time. CrUX history, LCP/CLS/INP breakdowns and performance experiments

- Extension ID: `mcffmgagphgpgkdclllnilokablhjcge`
- Developer: [MarketingTracer](https://extensiontracker.com/developer/u389db05ec5aa34cf1d5c95f1cd261bc4)
- Enhanced Safe Browsing: Trusted ([what this means](https://extensiontracker.com/enhanced-safe-browsing))
- Category: [Productivity › Developer Tools](https://extensiontracker.com/category/productivity/developer)
- First published: 2022-10-29
- Last updated: 2026-10-10
- Version: `1.22`
- Size: 2.34 MiB
- Minimum Chrome: 88
- Languages (1): English
- Website: `corewebvitals.io`
- Support page: `https://www.corewebvitals.io/contact`
- Chrome Web Store: <https://chromewebstore.google.com/detail/core-web-vitals-visualize/mcffmgagphgpgkdclllnilokablhjcge>
- View its code or download CRX: <https://crxpeek.com/extension/mcffmgagphgpgkdclllnilokablhjcge>
- Search Google for the ID: <https://www.google.com/search?q=%22mcffmgagphgpgkdclllnilokablhjcge%22&tbs=li:1>

## Users over time

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

| Checked | Users | Rating | Ratings |
| --- | ---: | ---: | ---: |
| 2026-11-09 | 10,000 | 4.95 | 19 |
| 2026-11-01 | 10,000 | 4.95 | 19 |
| 2026-10-25 | 10,000 | 4.95 | 19 |
| 2026-10-17 | 10,000 | 4.95 | 19 |
| 2026-10-10 | 10,000 | 4.95 | 19 |
| 2026-10-05 | 10,000 | 4.95 | 19 |
| 2026-09-28 | 10,000 | 4.95 | 19 |
| 2026-09-27 | 10,000 | 4.95 | 19 |

## What changed

Every change found on a check, newest first.

- 2026-10-17: New version `1.22`, replacing `1.21`.

## Developer history

Moves to another publisher account and new contact emails, newest first.

No move to another account and no new contact email since tracking began on 2026-09-27.

We know contact emails only by a keyed hash, so they're never shown. Recent changes: [Account and contact changes](https://extensiontracker.com/owners/).

## 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 where it runs scripts

- `http://*/*`: Every website
- `https://*/*`: Every website

### Browser features

- `debugger`: Use Chrome's debugger on your tabs, which gives full control of their pages

## More from this developer

Other extensions from the same publisher account.

| Extension | Users | Rating | Ratings | Category |
| --- | ---: | ---: | ---: | --- |
| [CLS Visualizer](https://extensiontracker.com/extension/jbbeihojggidiclbcneckhcblilapahn) | 9,000 | 4.36 | 11 | Developer Tools |
| [Website Cache Warmer](https://extensiontracker.com/extension/feklbbdbjcadocpcahpoejfiobllncoe) | 308 | 3.80 | 5 | Developer Tools |

All 3 extensions by [MarketingTracer](https://extensiontracker.com/developer/u389db05ec5aa34cf1d5c95f1cd261bc4).

## About this data

Collected from the extension's public Chrome Web Store listing. It's checked every week, because it has 1,000 or more users, and again whenever a new version appears. Last checked 2026-11-09 06:02 UTC; next check around 2026-11-16.

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

## Cite this page

Extension Tracker. “Core Web Vitals Visualizer” (mcffmgagphgpgkdclllnilokablhjcge). Chrome Web Store data, last checked 2026-11-09. https://extensiontracker.com/extension/mcffmgagphgpgkdclllnilokablhjcge. Accessed 2026-11-13.

```bibtex
@misc{extensiontracker_mcffmgagphgpgkdclllnilokablhjcge,
  title   = {Core Web Vitals Visualizer (mcffmgagphgpgkdclllnilokablhjcge)},
  author  = {{Extension Tracker}},
  year    = {2026},
  note    = {Chrome Web Store data, last checked 2026-11-09},
  url     = {https://extensiontracker.com/extension/mcffmgagphgpgkdclllnilokablhjcge},
  urldate = {2026-11-13}
}
```

---

From Extension Tracker, a public record of the Chrome Web Store: <https://extensiontracker.com/extension/mcffmgagphgpgkdclllnilokablhjcge>. 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. Every page except search comes as Markdown too: add `format=md` to the address, as in `https://extensiontracker.com/extension/{id}?format=md`.