How to Check What an AI Changed in Your Original Text

Start with these choices

Turn changed terms into a review list

The example changes dates and the party paying shipping. Do not approve a change merely because the diff found it. Record the original value, proposed value and person who can confirm it: a schedule owner for dates, and the person responsible for the agreement for cost terms.

Use the source and revision below as review practice. The linked insight explains separately how line and word modes count changes.

납품일: 2026년 10월 15일
대금 지급: 검수 후 30일 이내
운송비는 공급자가 부담한다.

납품일: 2026년 10월 30일
대금 지급: 검수 후 45일 이내
운송비는 구매자가 부담한다.
하자보증기간은 24개월이다.

- 15
+ 30
- 30
+ 45
- 공급
+ 구매
+ 하자보증기간은 24개월이다.

• Download file · TXTSource TXT for repeat comparison
• Download file · TXTRevision TXT
• Read related articleWhy line and word modes count changes differently

Confirm preserved meaning before judging style

An AI revision can read well while changing the message. It may compress a sentence it considers repetitive, turn a cautious statement into a firm one, or omit an exception that appears secondary in context.

Your first question should therefore be whether the same person must do the same thing at the same time and under the same conditions. Style preferences can be reviewed after meaning is secure.

• Was the responsible person or organization retained?
• Did may, should, and must keep the same strength?
• Were not, except, unless, and other limits preserved?
• Are numbers, units, dates, versions, and proper names unchanged?

Freeze the source before you compare

Repeatedly replacing text in one document makes it hard to know which wording was original. Treat the source as read-only and work on a separate revision. Names such as report_source and report_AI_revision_1 are simple but effective.

Also confirm that copying did not omit part of the document. Compare the first and last sentences, and inspect tables, footnotes, and lists in the original application because their structure can change during copying.

Line and word comparisons answer different questions

Line comparison is useful for finding a paragraph that was added, removed, or moved in a long document. Think of it as a map of the revision. Word comparison is better for discovering that ‘may’ became ‘must’ or that one number changed inside a sentence.

Starting with word comparison across a long rewrite can produce so many small marks that important changes become harder to see. Narrow the document with line comparison, then inspect selected passages at word level.

Hide whitespace changes only on a second pass

Copying an AI answer often changes line breaks and spaces, so formatting differences can outnumber meaningful revisions. Options that ignore whitespace, blank lines, or letter case can create a cleaner second view.

Do not hide them blindly. Indentation in Markdown, tables, code, file paths, passwords, and identifiers can use spaces or case as real data. First confirm that you are reviewing ordinary prose, then filter cosmetic differences.

Use a separate checklist for facts and reversals

Small factual changes are easy to miss while reading full paragraphs. Scan the marked changes specifically for numbers, percentages, currency, dates, times, versions, and the names of people, companies, and products.

Short terms such as not, except, before, after, maximum, and minimum can reverse a conclusion. For contracts, submission rules, medical, legal, or financial information, use the comparison as a first review and verify the final wording with the source or a qualified reviewer.

Compare the final version with the original once more

After accepting selected edits, compare the final version directly with the untouched source—not only with the first AI output. This reveals unintended changes accumulated during review.

Open the final document in its actual delivery format to check tables, lists, links, and paragraph order. Keep the source, AI revision, and final copy with distinct names. A diff points to changes; it does not decide which wording is correct.