Requestly Alternative: An Honest Comparison
Requestly and Header Forge are not really the same category, and pretending otherwise would not help you choose. Requestly is a broad HTTP interception platform. Header Forge does one part of that job and tries to do it without ads, accounts, or a subscription. Which one you want depends almost entirely on whether you need the rest of the platform. We build Header Forge, so check both listings yourself.
What Requestly does that Header Forge cannot
This list is the honest reason to choose Requestly, and none of it is on our roadmap as a like-for-like replacement:
- Response body mocking and overriding: returning a modified or entirely fake JSON payload. Chrome’s declarativeNetRequest, which Manifest V3 extensions use for this work, cannot rewrite response bodies at all, so this is a capability difference, not a pricing decision. See why Manifest V3 changed header extensions.
- Script injection: running your own JavaScript or CSS on matching pages as part of a rule.
- Interception beyond the browser: their desktop tooling reaches traffic from other applications. An extension is confined to the browser.
- Team workspaces and shared rules: collaboration is a core part of their product. Header Forge has no cloud and no account, which is exactly why it cannot share anything.
- Session recording for bug reports: capturing a reproducible session with network context attached.
If you need any of those, the comparison is over: use Requestly, or a proxy such as mitmproxy or Charles for the parts that live outside the browser.
Why people move to something smaller
- The account requirement. Signing in to change a header is friction, and on a locked-down work machine it can be a blocker rather than an annoyance.
- Free-tier limits that reach into existing work. The complaint we heard repeatedly, and designed against, is passing a rule cap and finding you can no longer edit rules you already made. Verify their current limits on their pricing page, because these terms change.
- Subscription pricing for occasional use. If you set three header rules a month, a recurring bill for a platform you barely touch is hard to justify.
- Scope. A tool that mocks APIs, injects scripts, records sessions, and syncs a team is a lot of surface area when all you wanted was an Authorization header.
Side by side
Header Forge details are current and precise. Requestly details are described carefully and may have changed, so confirm before deciding on any single row.
| Header Forge | Requestly (verify current terms) | |
|---|---|---|
| Scope | headers, redirects, and request blocking | a full HTTP interception platform |
| Account required | no, ever | yes |
| Cloud storage of your rules | none, everything is local | yes, and that is the point of it |
| Response header editing | free | available, check current tier limits |
| Response body mocking | not possible under declarativeNetRequest | yes, a core feature |
| Script injection | no | yes |
| Free limits | 20 rules, 5 profiles | check their pricing page |
| Behavior over the free limit | existing rules keep running, you cannot add more | historically restrictive, verify current behavior |
| Pricing model | one-time $34.99 | subscription |
| Import Requestly rules | one click, free tier | not applicable |
Migrating your rules
- Export your rules from Requestly as JSON.
- Import the file into Header Forge. The format is detected automatically, no format picker involved.
- Header rules convert directly: each source pattern becomes a match, and each request or response modification becomes a header operation. Removals convert as removals.
- Redirect rules convert too. Redirects are a Pro feature in Header Forge, and imported ones keep running on the free tier with a note that they rely on Pro.
- Rules that depend on response body modification or script injection have no equivalent and will not come across. If those are load-bearing for you, that is your answer about which tool to use.
- Verify one rule in DevTools before trusting the whole import.
Match operators map as you would expect: equals becomes a domain match, contains becomes a contains match, wildcard becomes wildcard, and matches becomes regex. Because regex is a Pro match type, imported regex rules are flagged, and they keep applying regardless.
Choosing
| If you need | Choose |
|---|---|
| To mock or rewrite response bodies | Requestly, or a proxy |
| To inject scripts into pages as part of a rule | Requestly |
| To share one rule set across a team | Requestly |
| To intercept traffic from apps outside the browser | a proxy such as mitmproxy or Charles |
| Header work with no account and no subscription | Header Forge |
| Everything local, with nothing uploaded | Header Forge |
| To keep working when you pass a free limit | Header Forge |
Common questions
Can Header Forge mock an API response?
Not the body. Manifest V3 extensions modify requests through declarativeNetRequest, which cannot rewrite response bodies. You can redirect a request to a different URL or to a local file, and you can change status-adjacent behavior with headers, but returning invented JSON in place of a real response is outside what the API allows. Requestly and proxy tools do this properly.
Do I need an account to use Header Forge?
No, and there is nothing to sign into. Rules live in your browser profile. The only network calls the extension makes are an anonymous license check and optional anonymous usage events you can turn off.
Will my Requestly rules import cleanly?
Header and redirect rules convert, along with their match patterns and enabled state. Anything relying on response body modification or script injection has no equivalent and is skipped. Check one imported rule in DevTools before assuming the rest are fine.
Is a one-time purchase really cheaper?
For a utility you use for years, yes, and that is the pitch. If you need Requestly’s platform features, the subscription is buying you something Header Forge does not have, and the comparison is about capability rather than price.