Takeout gave me a .tgz file and nothing will open it
You chose .tgz on the Takeout screen, or it was already selected, and now Windows does nothing at all when you double-click the file. It is not broken and it is not a failed download.
Can you get it back?
Yes. It is an ordinary archive in a format Windows has no handler for. One free tool opens it.
What actually happened
Google offers .tgz next to .zip on the same screen and the difference is not explained. A .tgz is two formats nested: a tar archive holding your files, compressed with gzip. Windows understands neither on its own, so a double-click does nothing.
This is also why extracting it feels like it takes two goes. Unpacking the gzip layer leaves you with a .tar, which then has to be unpacked in turn. Some tools do both in one step and some do not, which is where most of the confusion comes from.
This is not a preference. A zip carries an index at the end, so a tool can jump straight to any file inside without touching the rest. A gzip stream cannot be read out of order at all, so anything reading a .tgz has to work through it from the beginning. For a small export the difference does not matter. For a Takeout measured in tens of gigabytes it is the difference between opening it and unpacking all of it first, and you have to double your free disk space to unpack it.
How to fix it
One tool, and on Windows it may take two passes.
- 7-Zip on Windows
- Right-click the file, 7-Zip, Extract here. That gives you a .tar. Right-click that and extract it too, and your files are there. Free, and it is the reason most people install 7-Zip in the first place.
- macOS and Linux
- Double-click works on macOS. In a terminal on either, tar -xzf takeout.tgz does both layers in one pass.
How Muletto does it
Muletto reads .tgz directly, without an unpacking step and without needing the free space a full extraction would want. Because a gzip stream cannot be read out of order, it is unpacked in one pass as it goes rather than being read lazily the way a zip is.
Stopping it happening again
On the Takeout screen, set the file type to .zip before you request. It is a dropdown next to the delivery method and it is easy to scroll past.
The .tgz reader was verified in the browser against a gzipped tar built to specification, checking every member size and reading a 3 MB member back byte for byte.