---
title: "Modify HTTP Headers (HTTP Header) - FlexHeader – Chrome extension stats, history and permissions"
description: "7,000 users, rated 4.87 by 31 people. Version 1.11.2, updated 2026-09-11. Requests 3 permissions."
url: "https://extensiontracker.com/extension/gffpeamhhldhibdngenbfciboinanppf"
---

# Modify HTTP Headers (HTTP Header) - FlexHeader

Live in the Chrome Web Store.

- Users: 7,000
- Rating: 4.87 from 31 ratings
- Last checked: 2026-11-08 13:36 UTC
- Users gained in 7 days: No change
- Users gained in 30 days: No change (+0.0%)
- Rank by users: #8,681 of 292,125 live extensions
- Rank in Developer Tools: #798 of 30,444

## The listing

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

Summary from the listing:

> Add, modify & delete HTTP request/response headers with URL & regex rules. Open-source, private, no data collection

- Extension ID: `gffpeamhhldhibdngenbfciboinanppf`
- Developer: [Harrison Deo](https://extensiontracker.com/developer/ua26db2b9b43d9a66216cb6bdf4ca66b0)
- 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: 2023-08-19
- Last updated: 2026-09-11
- Version: `1.11.2`
- Size: 188 KiB
- Minimum Chrome: 88
- Languages (1): English (United Kingdom)
- Website: `harrisondeo.me.uk`
- Support page: `https://github.com/harrisondeo/FlexHeader`
- Chrome Web Store: <https://chromewebstore.google.com/detail/modify-http-headers-http/gffpeamhhldhibdngenbfciboinanppf>
- View its code or download CRX: <https://crxpeek.com/extension/gffpeamhhldhibdngenbfciboinanppf>
- Search Google for the ID: <https://www.google.com/search?q=%22gffpeamhhldhibdngenbfciboinanppf%22&tbs=li:1>

## Users over time

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

| Checked | Users | Rating | Ratings |
| --- | ---: | ---: | ---: |
| 2026-11-08 | 7,000 | 4.87 | 31 |
| 2026-11-01 | 7,000 | 4.87 | 31 |
| 2026-10-26 | 7,000 | 4.87 | 31 |
| 2026-10-19 | 8,000 | 4.87 | 31 |
| 2026-10-13 | 7,000 | 4.87 | 30 |
| 2026-10-05 | 7,000 | 4.87 | 30 |
| 2026-09-29 | 7,000 | 4.86 | 29 |
| 2026-09-27 | 7,000 | 4.86 | 29 |

## What changed

Every change found on a check, newest first.

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

## 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

- `<all_urls>`: Every website

### Browser features

- `declarativeNetRequest`: Block or change network requests, using rules
- `storage`: Save settings and data in your browser

## 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 2026-11-08 13:36 UTC; next check around 2026-11-15.

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

## Cite this page

Extension Tracker. “Modify HTTP Headers (HTTP Header) - FlexHeader” (gffpeamhhldhibdngenbfciboinanppf). Chrome Web Store data, last checked 2026-11-08. https://extensiontracker.com/extension/gffpeamhhldhibdngenbfciboinanppf. Accessed 2026-11-13.

```bibtex
@misc{extensiontracker_gffpeamhhldhibdngenbfciboinanppf,
  title   = {Modify HTTP Headers (HTTP Header) - FlexHeader (gffpeamhhldhibdngenbfciboinanppf)},
  author  = {{Extension Tracker}},
  year    = {2026},
  note    = {Chrome Web Store data, last checked 2026-11-08},
  url     = {https://extensiontracker.com/extension/gffpeamhhldhibdngenbfciboinanppf},
  urldate = {2026-11-13}
}
```

---

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