Label the documents Old and New, define the comparison scope and ask for a change table with source locations in both versions. Keep wording changes separate from their possible effects. Check additions, deletions, tables and important unchanged passages before using the summary.
What you need before you start
Two documents appear similar but a changed sentence, missing section or new condition could matter.
Bring: Both permitted files with clear version labels, the question you need answered, comparison scope and any sections that are especially important.
Start with these steps
- Name the versions and define what counts as a material difference.
- Ask for a table with location, old wording, new wording, change type and possible effect.
- Request explicit rows for omissions and unchanged clauses.
- Open every decisive passage and check tables, footnotes and formatting.
- Save the checked comparison with the two source versions and open questions.
A prompt you can adapt
Compare Old [version] and New [version] for [purpose]. First align the sections. Then list material additions, deletions, wording changes and moved text. For each row show the old and new location, short exact passages, change type and possible effect. Mark interpretation separately from textual fact. Include critical unchanged clauses. Account for every section as compared or out of scope. Do not call a summary an exact complete diff.
Replace every bracket with real information. Remove fields that do not affect your task.
What this looks like in practice
Teaching example: Old says requests must arrive within 30 calendar days of delivery. New says within 14 calendar days of approval. Both the number and the event starting the clock changed. A summary saying only 'the deadline is shorter' misses a key difference.
Decide whether you need exact changes or their meaning
Two documents can differ in several ways. You may need every changed word, a list of changes that affect a process, or a short explanation for a colleague. These are different outputs. Tell ChatGPT which one you need. A readable summary is useful, but it does not prove that every word was compared.
For an exact word comparison, a document editor's compare function or a text diff tool can provide a strong starting record. ChatGPT can help explain and group that record, while pointing back to the source. This is often faster and more reliable than asking a chat to notice every tiny edit in a long document.
For practical effects, state the decision. You might need to update a request form, identify changed responsibilities or understand what a new proposal adds. This lets the comparison prioritize meaningful differences without pretending that punctuation and a new deadline have the same importance.
Label the versions and check what can be read
Name the files clearly, such as Policy Old v1 and Policy New v2. Include dates or version identifiers when they exist. Say which direction you are comparing. A table with old and new reversed can produce the wrong action even if the quoted passages are accurate.
Check whether text can be selected and copied from both files. A scan may need OCR, which means converting printed characters in an image into text. Keep page references and inspect uncertain passages. A badly extracted table can create a false change between two otherwise identical versions.
Ask ChatGPT which parts it could use. Long files, images, footnotes and unusual formatting may need separate attention. Uploading two files does not by itself establish that every page was examined. If only a few sections matter, name them and keep the remainder explicitly out of scope.
Align sections before comparing sentences
A new version may reorder the document. Old section four may become new section six without a change in meaning. Ask for a section map using stable headings or subjects as well as page numbers. Pagination often shifts after a new paragraph is inserted, so page numbers alone are a weak match.
Give each section one status: matched, added, deleted, moved or not yet compared. Check the map before using the change list. If two sections have similar names, compare the content instead of assuming they are equivalent. A new appendix may carry an exception that disappeared from the main text.
For long documents, compare named sections in manageable batches. Keep a small amount of surrounding context where it controls the meaning. Combine the findings by source references and remove duplicate rows caused by overlap. This gives you a visible coverage record instead of an unexplained claim of completeness.
Teaching example: compare a small internal procedure
This teaching example uses made-up internal procedure text. It is not a real policy or legal advice. Old section two says: Submit requests within 30 calendar days of delivery. Old section three says: Team A reviews each request. Old section four says: Missing information may be supplied within seven calendar days. New section two says: Submit requests within 14 calendar days of approval. New section three says: Team B reviews each request. The supplied New text has no section four. Both versions say in section one: Include the request ID.
The comparison needs separate rows for the deadline, owner and missing-information clause. The unchanged request-ID requirement is worth retaining because the form still needs it. The absence of section four is a textual observation within the supplied material. Before concluding that the opportunity to supply missing information has ended, inspect the rest of New for the same rule under another heading.
The change table below shows both facts and questions. It does not turn an unconfirmed practical effect into settled policy.
| Item | Old | New | Meaning to check |
|---|---|---|---|
| Deadline, section 2 | 30 calendar days of delivery | 14 calendar days of approval | Duration and starting event both changed |
| Reviewer, section 3 | Team A | Team B | Update routing if effective |
| Missing information, section 4 | Seven-day opportunity | Not found in supplied New text | Check full New document for moved rule |
| Request ID, section 1 | Include the request ID | Include the request ID | Unchanged requirement |
Separate changed wording from practical effect
The text establishes that thirty changed to fourteen and delivery changed to approval. It does not establish the date of approval in any particular case. You cannot calculate a real deadline without that date and the rule's other conditions. Even saying the deadline is always earlier can be wrong when the event starting the clock also changed.
Ask ChatGPT to use two columns: what the text says and what that may require in practice. Team A to Team B is a clear wording change. Faster handling is only a possible outcome unless another source supports it. Keep that distinction even if a short summary would sound more confident.
Definitions can control the effect. If the document defines approval in a separate section, compare that definition too. A familiar word may have a special meaning in the document. The main sentence, the definitions and the exceptions should be read together before you act.
Look for deletions, moved rules and exceptions
A deleted paragraph can matter more than ten edited words. Request explicit rows for omissions. For each important deletion, search the new version for the same topic, key phrase and related heading. The content may have moved or been rewritten. Report not found within the reviewed material when that is the honest result.
Check tables, footnotes and appendices. A fee may stay the same in a paragraph while a table changes who pays it. A footnote may add a limit that alters an otherwise unchanged sentence. Ask for cross-references that now point to a different or missing section.
In the teaching example, the missing-information rule is unresolved until the complete new version is checked. The safe action is to ask where that rule now appears or whether its removal was intended. Do not silently delete it from the working process merely because a partial comparison did not find it.
Keep exact passages short and easy to locate
Request the location and the short passage that proves each change. A section heading, paragraph opening and page reference can work together. Do not quote a full page when one sentence shows the difference. Long extracts make the table harder to inspect and can hide the words that changed.
Check the original file for each decisive row. Make sure the quoted words are exact and that a nearby sentence does not qualify them. If ChatGPT paraphrases the old text in a column labelled exact wording, ask for a correction. A paraphrase can erase the very difference you are trying to understand.
Keep evidence identifiers stable. If row C3 explains a changed owner, use C3 in the action list. This lets someone trace a requested process change back to the comparison and then to both originals. A short chain of references is easier to maintain than repeated paragraphs of explanation.
Repair a comparison that misses the important change
Suppose the teaching output says: The request deadline fell from thirty to fourteen days. That is incomplete because it ignores the change from delivery to approval. A targeted repair is: Compare the entire deadline sentence, identify both changed elements and avoid claiming the new deadline is always earlier. Keep the verified owner change.
If the output says the missing-information option was removed, ask it to qualify the finding: The clause is absent from the supplied New sections; the full document still needs checking for moved content. This keeps the confirmed observation while correcting the unsupported conclusion.
If the comparison lists a moved paragraph as a deletion and addition, ask for a section alignment check. A moved-but-unchanged category reduces noise. You can then focus on the changes that actually affect duties, dates, amounts or exceptions.
Turn the checked differences into an action list
After the comparison is checked, ask what needs to change in your workflow. Each action should point to a comparison row. For the teaching example, actions might include confirming the effective date, updating the form's deadline wording and routing new requests to the named team once the procedure takes effect.
Keep unresolved questions separate. Does the new version apply to requests already in progress? Where is the missing-information rule? Who owns the approval date? The document may answer these elsewhere, or the document owner may need to clarify them. Do not let ChatGPT invent transition rules to make the checklist complete.
For contracts, regulations or another consequential document, use the change table to prepare focused questions for an appropriate specialist. A textual comparison helps locate issues; it does not settle enforceability or the correct interpretation of conflicting clauses. Keep the full context available to whoever makes that decision.
Save the sources, comparison and coverage record
Keep both original versions, the checked change table and the list of sections compared. Record any uncertain extraction or unexamined appendix. If a third version arrives, label it separately and decide whether you need Old to Newest, New to Newest, or both. Do not overwrite a source and lose the reference behind a prior decision.
Finish with a concise status: compared sections, confirmed material changes, open questions and next actions. A statement such as all supplied sections accounted for is clearer than complete when the supplied files may be partial. If you need exact completeness, reconcile the summary with the document compare or diff output.
The comparison is useful when another person can find the passages, understand which changes matter and see what is still uncertain. ChatGPT helps explain and organize the differences. The original versions remain the evidence for what changed.
Check the result before you use it
- Are the files and version direction correct?
- Can every reported change be located in the originals?
- Were deleted sections, tables, footnotes and definitions checked?
- Are moved passages distinguished from new content?
- Does the scope record show what remains unexamined?
Watch for: A smooth summary may miss an omission or explain a rule too broadly. Use original passages to check the changes that affect your decision.