NotebookLM "Failed to Upload Source": Causes and Fixes
Topics: #notebooklm failed to upload source #notebooklm youtube source is empty #notebooklm pdf not uploading #gemini notebook upload error all keywords ↓
In this guide
You drag in a PDF, wait… and NotebookLM (now Gemini Notebook) shows an error, or the source appears but is empty. Upload problems are among the most common frustrations, and most have simple fixes. Work through this checklist from top to bottom. It covers PDFs, Google Drive files, websites and YouTube links.
Supported source types (October 2026)
According to Google's help center, Gemini Notebook accepts:
- PDF, Word (.docx), text (.txt), Markdown (.md), CSV, PowerPoint (.pptx) and ePub files
- Google Docs, Google Slides (up to 100 slides) and Google Sheets (limited to 100k tokens at this time)
- Images (png, jpg, webp, heic and others) and audio files (such as MP3 and WAV)
- Web URLs, YouTube URLs of public videos, and copied text
- Eligible Google Play Books ebooks (text only)
Each source can be up to 500,000 words or 200 MB. The free plan allows up to 50 sources per notebook.
Fixes for files that won't upload
1. The file is too large
Split big PDFs into parts (by chapter) or compress images inside them. Remember the word limit too. A long book can pass 500,000 words even if the file is small.
2. The PDF is copy-protected or has a password
Google lists copy-protected PDFs as a reason for failed imports. Use a version without protection that you're allowed to use, or ask the owner for an unlocked copy. Never try to break protection on files you don't have rights to.
3. Unsupported format
Convert the file. For example, save .xlsx as CSV or open it in Google Sheets, and save .rtf or .odt as .docx or PDF.
4. Special characters in the filename
Users report that unusual symbols in filenames can cause problems. Rename the file to plain letters and numbers and try again.
5. You've hit the source limit
Delete unused sources (inactive ones still count) or split the project into two notebooks.
Fixes for Google Drive sources
6. No access to the file
You need at least view access. If the owner removed sharing or deleted the file, the source becomes inaccessible. Request access or remove it.
7. Changes don't show up
Drive sources sync automatically, but you can force an update: open the source and click Click to sync with Google Drive.
8. Comments and footnotes are missing
That's expected. Gemini Notebook doesn't import footnotes or comments from Google files.
Fixes for websites and YouTube
9. Website imports are empty or incomplete
Only the text of the page is imported. Images, embedded videos and linked pages aren't included, and paywalled pages aren't supported. Copy the text you're allowed to use and paste it as a text source instead.
10. YouTube source is empty
Only public YouTube videos are supported, and the import relies on the transcript. If a video has no captions, or is private or restricted, the source may be empty. Try another video, or upload an audio file you have rights to. For other options, see our guide to free AI tools to summarize YouTube videos.
Fixes for browser and connection issues
11. A browser extension is blocking the upload
Ad blockers, privacy extensions and PDF extensions are often blamed in user reports. Try an incognito/private window (extensions are usually off there). If that works, disable extensions one by one for the site.
12. Temporary glitch
Remove the failed source, reload the page and upload again. Check your connection, try a different browser, or wait a few minutes. Short service problems do happen.
Prevent problems next time
- Use clean, text-based PDFs (not scans) when possible.
- Name files clearly ("Smith 2024 – Climate adaptation").
- Keep notebooks focused rather than adding everything.
- Keep originals in Drive or a reference manager. See using NotebookLM with Zotero.
Need to get files back out instead? Read how to download sources from NotebookLM.
Still failing?
Use the feedback option inside Gemini Notebook to report the problem, and check the official help center and community forum for known issues. Include the file type, size and the exact error message.
Quick checklist (print or save)
- Supported file type?
- Under 200 MB and 500,000 words?
- No copy protection or password?
- Simple filename?
- Under the source limit for your plan?
- View access to the Drive file?
- Public, captioned YouTube video?
- Non-paywalled web page?
- Works in an incognito window?
- Removed and re-added after a reload?
Special cases
Audio files won't process
Long or noisy recordings can take time or give poor transcripts. Trim silence, use a common format such as MP3 or WAV, and make sure the file is under 200 MB.
Images and scanned pages
Image sources are supported, but Google notes that some types of images may not work as well. For scanned books or handouts, a PDF with selectable text (OCR) usually gives better answers.
Google Slides and Sheets limits
Slides are limited to 100 slides and Sheets to 100k tokens at the time of writing. Split very large decks or spreadsheets, or export just the parts you need.
Shared notebooks
If a collaborator added a Drive source you can't open, it may show as inaccessible for you. Ask the owner to share the original file with you.
Summary
Most "failed to upload source" errors come from size or word limits, protected PDFs, unsupported formats, missing Drive access, paywalled pages, caption-less YouTube videos or browser extensions. Check those in order, remove and re-add the source, and test in an incognito window. You'll fix the vast majority of upload problems in minutes.
Frequently asked questions
Why does NotebookLM say my source failed to upload?
Common causes include files over 200 MB or 500,000 words, copy-protected PDFs, unsupported formats, Google Drive files you can't access, paywalled web pages, or a browser extension blocking the upload.
Why is my YouTube source empty?
Gemini Notebook supports YouTube URLs of public videos and relies on their transcript. Private, unlisted or restricted videos, or videos without captions, may import with little or no content.
Does NotebookLM accept Excel files?
Google's consumer help lists Google Sheets (limited to 100k tokens at this time) and CSV files. If an .xlsx file doesn't upload, open it in Google Sheets or save it as CSV and add that instead.
Is there a limit on sources?
Free users can add up to 50 sources per notebook. Paid Google AI plans raise this limit. Inactive sources, for example Drive files you lost access to, still count toward the limit.
Will removing and re-adding a source help?
Often, yes. Delete the failed source, reload the page and upload again. If it still fails, try an incognito window to rule out extensions.
Why does my Google Doc say the source is inaccessible?
You may have lost access to the file, or it was deleted. Inactive sources still count toward your limit, so request access again or remove the source.
Can I upload a whole book?
Yes, if it stays within 500,000 words and 200 MB and you have the right to use it. Very long books may be easier to work with when split into chapters.