Dev tools · alternatives · 2026

24 alternatives to Open-Source HTTP Interceptor – Capture, Modify, Run Requests in Browser

Hey HN, I recently built an open-source HTTP interceptor called Relay, which works as a Chrome extension for capturing, modifying, and replaying HTTP requests directly in your browser — no account needed. How it works: Relay lets you capture requests as they happen, modify parameters, headers, or body content, and replay them on the fly. You can customize or debug network requests quickly without needing an external tool or complex setup. Key features: - Simple setup: Install the extension and start a session to capture requests. You can filter by URLs and methods. -Request modification:…

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Open-Source HTTP Interceptor – Capture, Modify, Run Requests in Browser launched in 2024; newer entries below may have overtaken it.

1. 1
   HTTP Mock – Intercept, debug and mock HTTP(S) with zero setup▲341

   Beautiful, cross-platform & open-source tools for debugging, testing and building with HTTP(S), on Windows, Linux & Mac.

   2019 · httptoolkit.tech · its alternatives →

2. 2
   Relay▲430

   An extension that adds Discord-style chat to every website

   2020 · its alternatives →

3. 3IR
   Intercept.rest – Faster API debugging▲89

   Sharing an internal tool that accelerated my development work 10-fold, especially with API debugging. Thought fellow developers here might find it useful. As a developer, I often have trouble reproducing errors at the client end. https://intercept.rest lets me debug and monitor API requests and responses. It is similar to the Network tab in Chrome Developer Tools but works for any API: mobile apps, webhooks, frontend etc. After I shared it with a close circle of friends, they found it incredibly useful and even found new use cases, I never imagined. Been a long time lurker here and…

   2018 · its alternatives →

4. 4
   Session Replays by Requestly▲518

   Debug web apps faster with record & replay

   2023 · requestly.com · its alternatives →

5. 5
   Request Interceptor Pro▲5

   Intercept, modify, and replay HTTP request son the fly

   Feb 2026 · chromewebstore.google.com · its alternatives →

6. 6
   We’re open-sourcing Requestly - HTTP debugging proxy for Web and Mobile▲54

   Hey HN! We’ve open-sourced Requestly (https://github.com/requestly/requestly) - A network debugging proxy for web & mobile apps. Requestly intercepts all HTTP(s) requests & responses and provides full control to developers to modify the request/response like rewriting request URL to hit different environment or returning different response for APIs/scripts. In addition to HTTP(s) interception & modification capabilities, Requestly also offers Mock Server [0] & recording the browser sessions [1] with video, console logs, & network logs stitched together. We use…

   2023 · github.com · its alternatives →

7. 7
   Nix Capture▲88

   Capture API requests for bug reports in seconds

   Feb 2026 · nixcapture.com · its alternatives →

8. 8
   Interceptor – mock AJAX requests at the browser level▲60

   Introducing Interceptor - A browser extension that mocks backend responses and how to use it.

   2018 · crypt.codemancers.com · its alternatives →

9. 9
   Requestly 2.0▲112

   Intercept & modify HTTP requests

   2021 · requestly.com · its alternatives →

10. 10
    Middleman▲136

    Intercept and modify and HTTP(S) request and response easily

    2024 · its alternatives →

11. 11
    Open source JavaScript library to record and replay the web▲353

    Embeddable session replay infrastructure on rrweb, the open source standard. Unbranded SDK, ingest on your domain, replay through your API. Free tier included.

    2018 · rrweb.io · its alternatives →

12. 12
    An API that takes a URL and returns a file with browser screenshots▲208

    A self-hosted API that takes a URL and returns a file with browser screenshots. - goodreasonai/ScrapeServ

    2025 · github.com · its alternatives →

13. 13
    Hurl – Run and test HTTP requests with plain text, curl and Rust▲223

    Hurl, run and test HTTP requests with plain text and curl. Hurl can run fast automated integration tests.

    2021 · hurl.dev · its alternatives →

14. 14
    Requestly▲148

    Debug & Modify HTTP(s) Requests - loved by 125K+ web devs

    2019 · requestly.com · its alternatives →

15. 15
    Postman Interceptor▲78

    Postman companion to sync cookies & capture network requests

    2020 · chromewebstore.google.com · its alternatives →

16. 16
    LambdaTest Chrome Extension▲191

    Cross browser testing by taking full-page screenshots

    2018 · testmuai.com · its alternatives →

17. 17
    HTTP Catcher▲81

    Web debugging proxy for iOS

    2019 · apps.apple.com · its alternatives →

18. 18
    Where Adblock+ injects 20K CSS rules, HTTPSB injects one▲221

    Point & click to forbid/allow any class of requests made by your browser. Use it to block scripts, iframes, ads, facebook, etc. - Adblock Plus memory consumption · gorhill/httpswitchboard Wiki

    2014 · github.com · its alternatives →

19. 19
    BugShot▲115

    Discover, fix, capture, and report bugs in one shot

    Jul 2026 · bug-shot.com · its alternatives →

20. 20
    inProxy▲65

    Free Cross-platform Web Debugging and Mocking tool

    2020 · its alternatives →

21. 21
    Capture▲113

    Fast browser API to capture, extract, & create from web

    2025 · capture.page · its alternatives →

22. 22
    HTTP Mock▲22

    Intercept, debug & mock HTTP(S) with zero setup

    2019 · httptoolkit.com · its alternatives →

23. 23
    Proxy API for Web Scraping▲84

    Get HTML from any page with a simple API call

    2023 · its alternatives →

24. 24AP
    A proxy service for debugging HTTP/S traffic▲75

    2017 · debugproxy.com · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →