Life & fun · alternatives · 2026

24 alternatives to Run custom JavaScript, each time you visit a website/domain

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 1 we have checked on their own sites, 1 of them free or with a free tier. Run custom JavaScript, each time you visit a website/domain launched in 2018; newer entries below may have overtaken it.

1. 1
   Pomeradofree▲179

   Turn any website into an API / MCP in minutes

   10d ago · pomerado.ai · its alternatives →

2. 2ES
   Execute, share, and rate arbitrary JavaScript in-browser▲5

   2015 · riskyclicks.click · its alternatives →

3. 3OE
   Optimize existing websites automatically with just a click▲7

   2014 · snapmobl.com · its alternatives →

4. 4RB
   Reusing browser JavaScript code on server▲7

   2012 · blog.elastic.io · its alternatives →

5. 5PM
   Practical Modern JavaScript▲7

   2017 · ponyfoo.com · its alternatives →

6. 6
   Offline JS Playground▲98

   Write, run, and test JavaScript snippets & JSON offline

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

7. 7
   Eloquent Javascript▲20

   A modern introduction to Javascript

   2014 · eloquentjavascript.net · its alternatives →

8. 8ET
   engine262 - the self-hosted JavaScript engine▲5

   2019 · engine262.js.org · its alternatives →

9. 9
   Share the DOM of any webpage in real-time▲6

   2021 · chrome.google.com · its alternatives →

10. 10
    Simple framework for JavaScript apps▲7

    2019 · github.com · its alternatives →

11. 11TW
    Turn websites into structured APIs▲7

    2015 · kimonolabs.com · its alternatives →

12. 12
    My weekend project - Common API for Javascript Engines▲5

    2011 · github.com · its alternatives →

13. 13PW
    Party Wave – get all your external JS libraries in one script tag▲5

    2014 · partywavejs.org · its alternatives →

14. 14SH
    Self-hosted website builder and light CMS▲6

    2014 · trybuilder.com · its alternatives →

15. 15
    A cross-platform JavaScript editor and runtime for local-first web app▲5

    Beta Soon Follow me on X @cp_lepage and @get_fullstacked

    2024 · twitter.com · its alternatives →

16. 16
    serve-scripts▲6

    Instantly run server scripts in browser

    2016 · github.com · its alternatives →

17. 17RD
    Rapidly Develop CRUD Web Apps with Locode▲6

    2022 · locode.dev · its alternatives →

18. 18
    webscript▲3

    Just choose a URL and type in a script. No servers, no deplo

    2015 · webscript.io · its alternatives →

19. 19SR
    Space Rock, a realtime JavaScript framework▲7

    2015 · space-rock.meteor.com · its alternatives →

20. 20
    Practical JavaScript▲5

    Free video course with live office hours every Sunday

    2016 · watchandcode.com · its alternatives →

21. 21RS
    Run/Schedule stand-alone scripts on a REST endpoint▲6

    2016 · serverlessly.io · its alternatives →

22. 22LJ
    Learn Javascript by interactive coding▲5

    2012 · learnjs.info · its alternatives →

23. 23
    Build and run automations in the browser with natural language▲6

    2023 · youtube.com · its alternatives →

24. 24
    Run ping/ DNS lookups from multiple locations around the world▲6

    2021 · geonet.shodan.io · 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 →