How do I see every API call a page makes?
Open the RequestFox side panel and press Start, or press Alt Shift S (Option Shift S on a Mac). Every fetch, XMLHttpRequest, WebSocket frame and server-sent event appears the moment it starts, across tabs, frames and pop-ups, even calls a service worker answers. Each call is tied to the click or form submit that caused it.
How do I find failed or slow API calls?
You don't have to look for them: they are flagged as they happen, with what went wrong in plain words.
- FAILED refused, timed out, or a 4xx/5xx answer
- SLOW past your threshold, marked live while it waits
- RAPID 140ms the same call fired twice
- GRAPHQL ERROR an error hidden inside a 200 OK
- Token expired a 401 caused by an expired JWT
- SCHEMA CHANGED the answer's shape changed since last time
Can I replay or edit a request?
Yes. Replay any captured call as it was, or edit it first. Compose builds new requests with environments, {{variables}}, OAuth 2.0, OAuth 1.0a, JWT Bearer, AWS Signature v4 and saved collections, sent with the page's own cookies while recording, or from the extension itself. Several requests can stay open at once, and a cookie jar you switch on per site carries a sign-in to your next sends.
Can I mock an API response without changing the backend?
Yes. A rule can return the answer you choose, make a call fail, slow it down or pause it so you can edit it. Calls you changed carry a MOCKED or SIMULATED label, so nobody mistakes them for real bugs.
Can I import my Postman collection?
Yes. RequestFox imports collections and specs from these (from a file, a whole folder or a URL), and exports Postman collections, collections for Bruno, Insomnia and Hoppscotch, and OpenAPI 3.0 back out:
- Postman
- Insomnia
- Bruno
- Hoppscotch
- Thunder Client
- OpenAPI 3
- Swagger 2
- HAR
- cURL
Can I turn recorded traffic into tests?
Yes. Add checks to an endpoint (status, time, fields, a JSON Schema), chain saved requests into suites, run the same checks in CI with the downloadable command-line tool, or generate scripts from a recording:
- Playwright
- Cypress
- k6
- JMeter
- Gatling
- Locust
Where RequestFox fits
Instead of the Network panel
when you want problems flagged for you, sessions kept in History, and evidence you can export.
Next to an API client
when you want the calls your real app makes, with its cookies, rather than requests typed by hand.
Not for traffic outside the browser
Mobile and desktop apps need a proxy-based tool. RequestFox sees what a browser tab sends.
Compare RequestFox with Postman, DevTools, Insomnia, Bruno and Hoppscotch
Facts
- Works in
- Google Chrome (side panel) and Mozilla Firefox (sidebar)
- Price
- Free, no paid tier
- Account
- None
- Where your data lives
- In your browser. There is no RequestFox server and no analytics.
- Secrets
- Authorization headers, cookies and secret-shaped fields redacted by default
- Interface languages
- 14
- Version
- 2.4.0, what changed
- Source code
- MIT licence; repository not public
- Made by
- AccessiSight
Questions
Is RequestFox free?
Yes. RequestFox is free, and our promise is written here: nothing you can use for free today will be put behind a paywall later. It has no ads, no account and no paid tier.
Does RequestFox send my data anywhere?
No. Everything RequestFox captures stays in your browser's storage on your device. There is no RequestFox server, no analytics and no account. Authorization headers, cookies and secret-shaped fields are redacted by default in everything RequestFox keeps, logs or exports (Compose shows the answer to your own request as it came; its Recent list keeps your last 100 sends, redacted, on this device until you press Clear), and site access is asked for only when you press Start, or, for the sites involved, when you send from Compose or run a test suite with nothing recording.
Is there a free Postman alternative that runs in the browser?
RequestFox is a free browser extension that composes and sends requests with environments, {{variables}}, auth helpers including OAuth 2.0 and saved collections, imports Postman, Insomnia, Bruno, Hoppscotch and Thunder Client collections, and exports Postman collections and collections for Bruno, Insomnia and Hoppscotch. Unlike a standalone client it also records the calls your web app really makes. It has no cloud workspace or team sync.
How is RequestFox different from the DevTools Network panel?
DevTools shows every request and leaves the judging to you. RequestFox flags failed, slow, duplicate and retried calls as they happen, ties each one to the click that caused it, checks your per-endpoint rules, and keeps every session so you can compare today's run with yesterday's. DevTools is better for a raw, live view of everything a page loads.