About Requestly
Requestly lets you intercept web traffic from inside the browser and change it: rewrite headers, redirect URLs, block requests, inject scripts or return mock responses for REST and GraphQL calls. The Chrome listing describes exactly that set, and it needs no proxy. For years this territory belonged to ModHeader, which is the reason to look at Requestly now.
ModHeader was pulled from the Chrome and Edge stores in July 2026 after researchers found a dormant browsing-history collector in the genuine extension. Requestly is a different case. Its HTTP Interceptor code is public on GitHub, mostly under the AGPL, the extension runs on Manifest V3, and the Chrome version was updated at the end of September 2026. BrowserStack, which acquired Requestly in May 2025, states in its privacy policy that Requestly does not sell personal data.
There are trade-offs. Requestly is a commercial product: the Chrome listing notes in-app purchases and Requestly's site sells paid team plans, so check what the free extension includes. The privacy policy is written for the whole company, not the extension, and it mentions analytics and sharing of combined data for promotional purposes. It also needs broad site access. It is the one we would use for request rewriting.
Pros and cons
- Modifies headers, redirects URLs and mocks API responses
- Open source interceptor, mostly under the AGPL
- Chrome version updated in September 2026
- Listed in both the Chrome and Edge stores
- Owned by BrowserStack, with paid team plans
- Privacy policy is company-wide, not extension-specific
- Firefox is a direct download, Safari covers only the API client
Permissions
It asks for access to all websites and the ability to observe and modify web requests, because intercepting and rewriting traffic is its purpose.
