Document comparison with ChatGPT

📝 Educational summary

Comparing two versions of a document by eye is time-consuming, tedious and risky.
With ChatGPT, you can automate comparative analysis: it detects similarities, differences and inconsistencies in a single prompt.
Result: a clear picture which highlights changes (additions, deletions, reformulations, etc.) and a summary.
It's a huge time-saver and a guarantee of reliability.

💡 To remember

• Use the benchmarking tool.

• Supply the type of document + purpose + target audience.

• Paste the two texts (A and B).

• Get a clear, structured table.

• Optional: request a summary of the differences.

⌨️ Prompt to copy and paste

Prompt principal - Comparative analysis

You're an expert in comparative document analysis.

Your task is to compare two documents according to the following instructions:

Objective:

Identify and present similarities, significant differences and any inconsistencies between document A and document B.

Your role:

You act as a professional and rigorous proofreader, specializing in comparative analysis. You must be precise, impartial and synthetic.

Technical details:

Presents the comparison as a structured table with the following columns:

- Page or section concerned

- Contents of document A

- Contents of document B

- Nature of difference (identical, minor modification, addition, deletion, contradiction, reformulation, etc.)

If possible, indicate the page or section numbers where the differences appear.

The table must be legible, with a clear layout.

Context (to be customized) :

Document type: [contract, internal policy, product sheet...].  

Comparison objective: [check consistency, detect additions, identify critical changes...].  

Analysis target audience: [lawyer, manager, marketing team...]

Here are the documents to be analyzed:

Document A :  

[Paste the text from document A here].

Document B:  

[Paste the text from document B here]

Optional :  

At the end of the analysis, a summary of the main differences is provided in the form of a bulleted list.

⚠️ Common mistakes to avoid

❌ Paste texts without specifying the type of document → the analysis will be too vague.
❌ Don't indicate the objective → the AI doesn't know what to focus on.
❌ Let sensitive data through (contracts with names, addresses, IBAN).
❌ Copy and paste the final table directly without proofreading → it may contain formal awkwardness.

✅ Practical tips

✨ Always specify type of document + purpose + target audience → tailor-made response.
✨ Using documents anonymized before gluing.
✨ Request a bulleted summary at the end to get to the point.
✨ If the table is too long → ask "Summarizes major differences only".
✨ Use this prompt for contracts, internal policies, product sheets, procedures, etc.

🚀 Putting it into practice

👉 Paste two anonymized extracts from internal documents (A and B).
Request benchmarking → check that differences are captured and request a summary of key changes.