# NotebookLM prompt: compare sources in a table

Source: https://nlmexporter.com/guides/prompts/source-comparison-table-prompt  
Section: Prompts  
Last verified: November 2026  
Plan: Free

Use it to compare products, vendors, policies or reports on fixed dimensions. Paste the prompt below into the NotebookLM (Gemini Notebook) chat and replace the parts in square brackets. It tells NotebookLM to answer only from your sources, cite them and flag what they do not cover.

## Quick facts

| Item | Detail |
| --- | --- |
| Works in | NotebookLM / Gemini Notebook chat, and the customise box of Studio items |
| Sources needed | One source per item being compared. |
| Cost | Free to copy. Saving it in the extension is free for up to 10 plain prompts. |

## The prompt

```text
Compare the sources on these dimensions: [DIMENSION 1], [DIMENSION 2], [DIMENSION 3], [DIMENSION 4].
One row per source. Keep each number with its unit, date and what it measures.
Write "not stated" for empty cells. Under the table, list differences in how the sources define the dimensions.

Use only the sources in this notebook. Cite the source for every claim. If the sources do not cover something, say "not covered in the sources" instead of filling the gap.
```

## How to use it

1. Open the notebook and tick only the sources this question is about.
2. Paste the prompt into the chat and replace every part in [SQUARE BRACKETS].
3. Open two or three citations in the answer to confirm they say what the answer claims.
4. Save the answer as a note, then keep it: [Export the table to Google Sheets](https://nlmexporter.com/guides/integrations/notebooklm-to-google-sheets).

## Adapt it

- Add a row of "what to verify" per item.
- Ask for the three differences that matter most for [DECISION].

> NotebookLM can misread or over-generalise a source. A prompt reduces that; it does not remove it. Check cited passages before you rely on an answer.

## Frequently asked questions

### What should be in the notebook before I use the compare sources in a table prompt?

One source per item being compared.

### How do I save this prompt in NotebookLM?

NotebookLM has no prompt library of its own. With NotebookLM Ultra Exporter you can save it to My prompts and insert it in the chat box by typing /. Free saves 10 plain prompts; variable templates, folders and backup need Pro.

### Why does the prompt ask NotebookLM to say what is not covered?

Because a grounded tool is most useful when it shows the edges of your sources. An explicit instruction to flag gaps reduces confident answers that the sources do not support.

## Related guides

- [NotebookLM to Google Sheets: tables, flashcards and quiz data](https://nlmexporter.com/guides/integrations/notebooklm-to-google-sheets)
- [NotebookLM prompt: article outline from sources](https://nlmexporter.com/guides/prompts/article-outline-from-sources-prompt)
- [NotebookLM prompt: executive summary](https://nlmexporter.com/guides/prompts/executive-summary-prompt)
- [NotebookLM prompt: Zettelkasten notes](https://nlmexporter.com/guides/prompts/zettelkasten-notes-prompt)
- [NotebookLM prompt: verifiable timeline](https://nlmexporter.com/guides/prompts/timeline-extraction-prompt)
- [NotebookLM prompt: glossary from your sources](https://nlmexporter.com/guides/prompts/glossary-from-sources-prompt)