No jargon, no gatekeeping.
Local Overrides is Chrome's built-in way to fake a response. It is great for quick edits and awkward for everything else. Here is exactly where the line is.
Overrides persist per origin and path in that folder. Files show a purple dot in the Network panel when they are being overridden.
| Need | Local Overrides | ProxyCeptor |
|---|---|---|
| Change response JSON | Yes (whole file) | Yes (whole body or deep merge) |
| Change status code (500, 401, 429) | No | Yes |
| Add latency | No (throttling is global) | Yes, per URL pattern |
| Patch one field and keep the rest live | No, the file is a frozen copy | Yes (merge-json) |
| Wildcard or regex URL matching | Limited | Yes |
| Redirect to another host | No | Yes |
| Share with QA or teammates | Copy the folder by hand | Export or cloud workspace |
| Use on a Smart TV | No | Yes (SDK) |
Use Local Overrides when you want to tweak CSS, a script or one static response for a few minutes on your own machine. Use a proxy interceptor when you need an API scenario you will run again, such as an error state, a slow endpoint, an expired token or a feature flag, or when someone else needs to see the same thing.
Yes, with Local Overrides you can replace the body and headers of a response with a local file. It cannot change the status code or add delay.
Common causes: DevTools is closed (overrides only apply while it is open), the folder permission was revoked, the URL has a changing query string, or the request is served by a service worker.
Not with built-in throttling, which slows the whole page. A per-URL delay rule in ProxyCeptor affects only the matched endpoint.
What changed, and who it hurts.
Manifest V3 removed blocking webRequest, leaving developers wondering how to modify response bodies. Here is why declarativeNetRequest cannot touch payloads and how modern interceptors bypass the limitation.
Deep breath. Here we go.
It flashes for 40 milliseconds on my machine and I have declared victory. Deep breath. Let us talk about loading states.
Create a free ProxyCeptor account to mock, delay, block and rewrite API traffic, then share the same rules with your team.