torch.cuda.is_available() returns false in colab

Make sure your Hardware accelerator is set to GPU.

Runtime > Change runtime type > Hardware Accelerator

In case anyone else comes here and makes the same mistake I was making:

If you are trying to check if GPU is available and you do:

if torch.cuda.is_available:
  print('GPU available')
else:
  print('Please set GPU via Edit -> Notebook Settings.')

It will always seem that GPU is available. Note you need to use torch.cuda.is_available() not torch.cuda.is_available.

Worked with all the versions mentioned above and I did not have to downgrade my CUDA to 10.0. I had restarted my colab after the updates which set my running machine back to CPU and I just had to change it back to GPU.

Temporal fix may be to try Cuda 10.0 as explained in here.

Something like this:

conda install pytorch torchvision cudatoolkit=10.0 -c pytorch

In future versions this may work.