---
title: "HTTP Header Spy – Chrome extension stats, history and permissions"
description: "9,000 users, rated 3.84 by 61 people. Version 3.0.0, updated 2026-09-05. Requests 7 permissions."
url: "https://extensiontracker.com/extension/agnoocojkneiphkobpcfoaenhpjnmifb"
---

# HTTP Header Spy

Live in the Chrome Web Store.

- Users: 9,000
- Rating: 3.84 from 61 ratings
- Last checked: 2026-09-26 21:45 UTC
- Users gained in 7 days: – (needs a week of history)
- Users gained in 30 days: – (needs a month of history)
- Rank by users: #7,867 of 264,703 live extensions
- Rank in Developer Tools: #722 of 27,615

## The listing

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

Summary from the listing:

> HTTP Header Spy enables you to inspect request- response headers and cookies right after page load with no extra clicks.

- Extension ID: `agnoocojkneiphkobpcfoaenhpjnmifb`
- Developer: [Michiel Roos](https://extensiontracker.com/developer/u99bab8e18a2b7356cbf890bb0a2e4c7a)
- Category: [Productivity › Developer Tools](https://extensiontracker.com/category/productivity/developer)
- First published: 2013-06-17
- Last updated: 2026-09-05
- Version: `3.0.0`
- Size: 293 KiB
- Minimum Chrome: 88
- Languages (6): English, Nederlands, español, русский, हिन्दी, 中文（中国）
- Website: `michielroos.com`
- Chrome Web Store: <https://chromewebstore.google.com/detail/http-header-spy/agnoocojkneiphkobpcfoaenhpjnmifb>
- View the code or download the CRX, in CRX Viewer: <https://robwu.nl/crxviewer/?crx=https%3A%2F%2Fchromewebstore.google.com%2Fdetail%2Fagnoocojkneiphkobpcfoaenhpjnmifb>

## Users over time

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

| Checked | Users | Rating | Ratings |
| --- | ---: | ---: | ---: |
| 2026-09-26 | 9,000 | 3.84 | 61 |

## What changed

Every change found on a check, newest first.

No changes found since tracking began on 2026-09-26.

## 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

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

### Sites where it runs scripts

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

### Browser features

- `activeTab`: The tab you're on, only after you click the extension
- `scripting`: Run scripts on sites it can reach
- `storage`: Save settings and data in your browser
- `tabs`: Read the addresses and titles of your tabs
- `webRequest`: Watch network requests on the sites it can reach

## More from this developer

Other extensions from the same publisher account.

| Extension | Users | Rating | Ratings | Category |
| --- | ---: | ---: | ---: | --- |
| [Xposer](https://extensiontracker.com/extension/mnnfjgnafollgnkkfgkfodfidahpmffa) | 24 | – | – | Developer Tools |

All 2 extensions by [Michiel Roos](https://extensiontracker.com/developer/u99bab8e18a2b7356cbf890bb0a2e4c7a).

## 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 2026-09-26 21:45 UTC; next check around 2026-10-03.

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

## Cite this page

Extension Tracker. “HTTP Header Spy” (agnoocojkneiphkobpcfoaenhpjnmifb). Chrome Web Store data, last checked 2026-09-26. https://extensiontracker.com/extension/agnoocojkneiphkobpcfoaenhpjnmifb. Accessed 2026-09-28.

```bibtex
@misc{extensiontracker_agnoocojkneiphkobpcfoaenhpjnmifb,
  title   = {HTTP Header Spy (agnoocojkneiphkobpcfoaenhpjnmifb)},
  author  = {{Extension Tracker}},
  year    = {2026},
  note    = {Chrome Web Store data, last checked 2026-09-26},
  url     = {https://extensiontracker.com/extension/agnoocojkneiphkobpcfoaenhpjnmifb},
  urldate = {2026-09-28}
}
```

---

From Extension Tracker, a public record of the Chrome Web Store: <https://extensiontracker.com/extension/agnoocojkneiphkobpcfoaenhpjnmifb>. 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`.