Tamper
Extension Delisted
This extension is no longer available in the official store. Delisted on 2025-09-17.
Extends the Developer Tools, lets you locally edit files served from the web using Mitmproxy.
Tamper is a chrome extension that lets you inspect and modify requests made by Google Chrome before they are served to the browser.
IMPORTANT: For Tamper to run you will need to install its companion app using `pip install`, find out more here https://dutzi.github.io/tamper/#install.
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After installing both the chrome extension and the pyhton package, you will see the Tamper panel in your devtools. Similar to the Network panel, the Tamper panel shows you a list of all requests made by this page. Click on one of these network requests and the response Chrome got will open in your default editor. Make the changes you need and save the file. Once you hit refresh, Tamper will serve Chrome the file you just saved.
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Tamper is an open source project, based on mitmproxy. Fork us on Github: https://github.com/dutzi/tamper
Latest reviews
I run pip install tamper and get this error Collecting tamper Downloading https://files.pythonhosted.org/packages/7d/99/e86a8d78fa47721192b55e01ebf03cf4a74ab213429123e90f7079d69e25/tamper-0.24.5.tar.gz ERROR: Command errored out with exit status 1: command: /Library/Frameworks/Python.framework/Versions/3.7/bin/python3 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/tmp/pip-install-o9ock6wr/tamper/setup.py'"'"'; __file__='"'"'/private/tmp/pip-install-o9ock6wr/tamper/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base pip-egg-info cwd: /private/tmp/pip-install-o9ock6wr/tamper/ Complete output (6 lines): Traceback (most recent call last): File "<string>", line 1, in <module> File "/private/tmp/pip-install-o9ock6wr/tamper/setup.py", line 60 print '\nWriting chrome native messaging manifest file (' + manifestFilename + ')' ^ SyntaxError: invalid syntax ---------------------------------------- ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
For anyone trying to install this, this project stopped working more than a year ago and for now we haven't seen an update. Consider this project dead.
Idea is good but execution is poor. The setup doesn't work at all, it quits with an invalid syntax error when doing the pip install tamper command.
the lack of doc made me look for other alternatives ...
Error starting proxy it saids. it did not do anything
Setup is a nightmare
Access denied to the ceritficate page: https://mitmproxy.org/doc/certinstall/webapp.html
Not for windows without python.
The installation doesn't work properly.
The installation is quite tricky, if your PC doesn't have Python 2.7.x, but I made it :). I know the proxy is run in the background, but it seems work properly (I think soo). I don't know why for some site (just for testing), when I finish modified a file (.js) and reload page, it's work but don't give me the correct result :(, my code maybe wrong or maybe Tamper doesn't carry my code? Note : For testing a site, I always use Debugger from Firefox to get the file name that I want to modified, it's quite handy there :)
Seems like a great idea... wish there was complete documentation for it... I have all the essentials installed, but the apparently the proxy is not configured correctly.... with a bit of documentation this might even work.... until then I won't know
