Compare your spreadsheets and find differences in ChatGPT
Bring two tables you need to compare. Define what counts as a match, find changed or missing records, and review the differences.
By At a glance
Use ChatGPT to compare two spreadsheets or tables you already work with. Explain what the records represent and which column identifies the same item. Ask for missing records, changed values, and unclear matches. Review the results against the originals before making changes. Optional sample files are available if you want to see an example first.
- A reviewable list of differences between your two tables.
- Use your own material; the example is optional.
- Refine the first answer, then check the details before using it.
What to bring
- Where to use it
- A ChatGPT conversation with pasted tables or available spreadsheet uploads
- Two tables with their headers, supplied as pasted text or files you are allowed to upload.
- What you want to compare and the column that identifies the same record.
Choose the tables to compare
Choose two lists that should describe related work, such as an old and new inventory list, contact exports, or project records. Keep copies of the originals.
Tell ChatGPT what each table represents and what makes two rows the same item. A repeated name is not always a reliable match.
Provide your tables and matching context
Attach supported spreadsheet files if uploads are available, or paste a small table with its headers. Keep the file or tab names visible.[1]
Find the differences in your tables
- Provide both tables, describe your goal, and name the matching column if you know it.
- Use the prompt and resolve any questions about matching before accepting comparisons.
- Check changed and unmatched records against the originals before deciding what to update.
Use this prompt
Use this reusable prompt
Compare the two tables I provide. My goal is [what I want to check]. First identify the columns and the proposed matching key. Ask me before matching if that key is unclear or not unique. Show records present in only one table, changed values for valid matches, and duplicate or missing keys that need review. Explain how you compared the values and which records you excluded. Preserve the originals and keep uncertain matches separate. [Attach your files or paste both tables with their names and headers]
Inspect assumptions and calculations
A useful comparison explains its assumptions. Ask for the source rows and matching rules when a result seems surprising or a number needs checking.
Use this prompt
Inspect a difference
Show the original values and source rows for [the item]. Explain why it was reported as different or unmatched. Identify any assumption that needs my confirmation.
Use this prompt
Check the totals
If you reported totals, show which rows, units, and time period each total covers. Recalculate from those source values. Keep duplicates and missing values visible, and explain exclusions.
Check the comparison against the originals
Optional sample tables and example
You can skip these optional sample files and use your own tables. They contain fictional invoice and ledger exports with changed and missing records.
Example result
Example (illustrative, not data)
Illustrative example
Present in both tables: review any changed values. Present in one table only: check whether the record is new, missing, or outside the intended period. Duplicate key: confirm how the rows should match before accepting a comparison.
What to notice
- These categories help organize review of your own records.
- A difference needs investigation before it becomes a correction.
Review differences before making changes
For financial work, have the responsible person review the matching rules and results before changing records. For another practical task, prepare an update from your notes.
Use only information your organization allows you to share with your AI tool. Keep the original material available when checking important details.
Find another task in ChatGPT at work.
Sources & approach
Guidance draws on the official product documentation linked here. Example inputs and outputs are illustrations. The prompts are starting points to adapt and review with your own work.
- Uploading files and audio to ChatGPTOpenAI · Accessed November 2, 2026
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