How to practice CUDA without a GPU (for free)

Fun fact: you don't actually need an expensive NVIDIA GPU to start learning CUDA. You can get hands-on experience entirely in the cloud — perfect for experimenting and practicing optimization techniques.

What I tried

1. Google Colab — free GPU access after phone verification. Great for small experiments and learning the basics.
2. Kaggle Notebooks — similar to Colab, includes GPUs and TPUs. Requires phone verification. Excellent for competitions.
3. Paperspace Gradient — offers free GPU instances, but often hits max capacity. Can be unreliable at peak times.
4. Lightning AI — free credits each month. Good for testing CUDA kernels and small ML workloads.
5. LeetGPU — more of a "CUDA playground" for testing your code, similar to LeetCode-style exercises.
6. CUDA Online Judge — online CUDA coding challenges. Helps improve algorithmic thinking on GPU.
7. Amazon SageMaker Studio Lab — free GPU-enabled notebooks, fully cloud-hosted.
8. Saturn Cloud — free tier with GPU access, great for larger experiments and longer-running kernels.

Key insight

You can start learning CUDA today, even without owning hardware. Focus on writing kernels, understanding memory hierarchy, and practicing parallel execution. Cloud GPUs give you a playground to experiment and prepare for when you eventually work on real hardware.