GitHub shows “Notebook not found” for my Jupyter .ipynb file

[F-mehran]

Hello everyone, I’ve been working on several projects in Jupyter Notebook and recently uploaded them to my GitHub repository.
However, whenever I try to open my .ipynb files directly on GitHub, I only get this message: “Notebook not found”
I’ve tried several fixes:
Re-uploading the file
Pushing again using Git
Making sure the repository is public
I’ve also put a file with small size in my github
Even checking on nbviewer.org
Unfortunately, nothing has worked so far - nbviewer also gives me a 404 error.
When I open the same notebook locally in Jupyter, it runs perfectly fine. Here’s an example of one file that won’t display.
Here’s an example of one file that won’t display: https://github.com/F-mehran/Machine-learning/blob/main/recommender_system/Collaborative_Filtering/Collaborative_Filtering.ipynb Does anyone know why GitHub might fail to render this notebook, or how I can fix it so it displays normally?
Thanks in advance for any help.

[aasimansari1]

The "Notebook not found" error on GitHub usually has one of these causes:

1. File too large (most common)

GitHub's notebook renderer has a 10MB limit. If your .ipynb is larger (common when it contains embedded images or large outputs), GitHub cannot render it.

Fix: Clear all cell outputs before pushing:

# Install nbstripout
pip install nbstripout

# Strip outputs from a single file
nbstripout your_notebook.ipynb

# Or set it up as a git hook (auto-strips on every commit)
nbstripout --install

2. Corrupted JSON in the notebook

If the .ipynb has invalid JSON, GitHub fails silently.

# Validate your notebook
python -c "import json; json.load(open(your_notebook.ipynb))"

3. GitHub rendering is temporarily down

GitHub's notebook renderer (nbviewer) sometimes has outages. Try opening via nbviewer.org directly:

https://nbviewer.org/github/<username>/<repo>/blob/main/notebook.ipynb

4. File not committed properly

git status  # check the file is tracked
git add your_notebook.ipynb
git commit -m "add notebook"
git push

Quick test: If the raw file is accessible at github.com/<user>/<repo>/raw/main/notebook.ipynb, the file is uploaded correctly and the issue is the renderer — use nbviewer as an alternative viewer.