As of 13 August 2026, AI can compare two versions of a contract.
This still needs a person who signs their name to it.
Can you do it?
5 minutesto a draft.
30 minutesto something you’d act on.
Cost, all in£0
Skill neededchat-fluent
Who has to check ityou
What the alternative costsThe alternatives listed here do not provide a sourced price for a solicitor's contract review.
If this goes wrong: a missed or misunderstood change affects what you sign or do, and the problem may only appear in a dispute.
What to actually do
Hand it to a person
The route this page recommends
A person who owns the outcome does this end to end, worth it when the failure is dear.
Use a tool built for this
Second choiceDo it yourself
The distant thirdA chat interface, chat-fluent skill, and roughly 30 minutes until you can act on the result.
How to actually do it
- Open the original and revised contracts and save them as clearly named files such as Contract A and Contract B.
- Check that both files contain selectable text; run OCR on any image-only scan before uploading it.
- Remove unnecessary personal information and upload both complete versions to an AI document tool, identifying which is older and which is newer.
- Paste the comparison prompt and ask the tool to quote each changed passage rather than summarising changes without references.
- Open both contracts beside the AI response and check every reported addition, deletion, amount, date, deadline and clause reference against the source files.
- Mark any change affecting payment, termination, liability, indemnity, renewal, employment, housing, business ownership or a dispute as a question for a UK solicitor before signing.
- Save the checked comparison with the two source contracts and send that pack to the solicitor if the change could affect your legal rights or financial exposure.
Prompt
Compare the two attached versions of this contract as a document comparison exercise, not as legal advice. Treat the older version as Version A and the newer version as Version B. Produce: 1. a concise summary of the important changes; 2. a table with the clause or page reference, Version A wording, Version B wording, change type such as added, deleted or amended, and the likely practical effect; 3. every changed date, deadline, payment amount, notice period, renewal term, termination right, liability limit, indemnity, confidentiality obligation, data protection obligation, governing law provision and dispute process; 4. wording that is unclear, internally inconsistent or missing from one version; and 5. a list of points that should be checked with a UK solicitor before signing or relying on the contract. Quote the documents exactly where possible. Do not invent text, page numbers or legal effects. If a passage cannot be read, label it unreadable rather than guessing. Finish by stating which points I can verify by comparing the files directly.
Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.
What it gets wrong
- AI identifies wording changes but does not reliably decide whether a change is legally favourable, enforceable or suitable for your circumstances.
- It can miss changes in scans, tables, footnotes, formatting or clauses whose meaning depends on another agreement.
- It cannot know whether the person supplying the files has permission to upload confidential or personal information.
- It does not take responsibility for the contract you sign or for decisions based on its comparison.
Even on a YES, the friction has a name: judgement under ambiguity, legal accountability and verification cost.
How we scored this
Five axes, each scored nought to two by hand: ten means AI carries the task cleanly, and the thresholds that turn a total into YES, PARTLY or NO are published in the methodology. Each axis name links to its definition.
| Axis | Score (0–2) |
|---|---|
| Output | 2 |
| Inputs | 2 |
| Verification | 1 |
| Liability | 1 |
| Effort delta | 2 |
| Total | 8 / 10 |
The methodology and its thresholds are published in full.
FAQ
- Can ChatGPT compare two contracts?
- Yes. Give it both complete, readable versions and ask for exact quotations, clause references and a list of additions, deletions and amended wording. Check every reported change against the files, because this is not professional advice.
- Can AI tell me which contract is better?
- It can highlight terms that appear more or less favourable, but it cannot reliably decide which contract is better for your circumstances. Ask a solicitor about changes affecting liability, termination, payment, renewal or disputes.
- Is it safe to upload a contract to AI?
- Only upload a contract when you are permitted to share it and you understand the tool's handling of uploaded files. Remove unnecessary personal and confidential information where possible, and do not upload another person's information without a proper reason or permission.
- Do I need a solicitor after an AI contract comparison?
- You may not need one for a basic check of obvious wording changes, but a serious or high-value agreement needs a UK solicitor to assess the legal effect. This is not professional advice, and AI does not take responsibility for what you sign.
Nearby answers
The business side of this task: Can AI compare two versions of a contract?
Assessed by gpt-5.6-luna (gpt-5.6-luna) on 2026-08-13, second-checked by an independent model. Wrong somewhere? Email [email protected] and it gets re-checked.
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