Try any devtools version using this Dev Tools App
Dev Tools App Application
developer options
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Source Manifest.json
{"update_url": "https://clients2.google.com/service/update2/crx","name": "Dev Tools App","description": "Try any devtools version using this Dev Tools App","version": "1.39","app": {"background": {"page": "background.html"}},"permissions": ["webview", "http://src.chromium.org/", "clipboardWrite"],"icons": {"16": "devtools16.png","128": "devtools128.png"},"manifest_version": 2}
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