How to check what changed in a contract before you sign it

The final version of a contract isn't always the one you agreed. How changes slip in, where to look, and how to compare two versions word by word in a few minutes.

By Memento · Updated 8 October 2026 · 3 min read

You negotiate a contract by email. A few drafts go back and forth, you agree on the terms, and then the final version arrives for signing: twelve pages, looking exactly like the last draft. Most people skim it and sign.

Usually that's fine. Occasionally a clause has changed: a notice period, a renewal term, a figure, a "not" added or removed. Sometimes it's a genuine slip from working on the wrong draft, sometimes it isn't. Either way, once you've signed, the change is yours.

How changes go unnoticed

Tracked changes are hidden. In Word, a document can contain tracked changes that don't show in some views. A "clean" copy may also have had changes accepted silently.
The final copy is a PDF. Converting to PDF removes any record of edits. You see a finished document and nothing else.
The layout shifts. When paragraphs move to a different page, comparing by eye becomes almost impossible.
Fatigue. By the fifth draft, nobody reads every word again.

Compare, don't reread

The reliable way is to compare the version you agreed with the version you're asked to sign, word by word, using software. It takes a minute and catches every changed word, including ones you'd never spot reading.

Keep a copy of the last version you agreed, saved somewhere you won't overwrite.
When the signing copy arrives, compare it with that version.
Read every highlighted change in context. A comparison shows what changed; you still need to judge what it means.

Our compare tool reads PDFs, Word files and plain text, so you can compare a Word draft against the PDF you were sent to sign. With "ignore spacing" on, re-wrapped lines and page breaks don't show up as changes, so only real wording differences are highlighted.

Try it: Compare documentsSee exactly what changed between two versions of a PDF, Word or text document, word by word.

Where changes matter most

If you only have time to look closely at a few things, look at these:

Numbers. Prices, deposits, salaries, percentages, penalties and caps on liability.
Dates and periods. Start date, minimum term, notice period, payment deadlines.
Renewal. Whether the contract renews automatically, and how you can stop it.
Small words. "May" versus "shall", "and" versus "or", "including" versus "limited to". These flip the meaning of a clause.
Names and parties. The legal name of the company you're dealing with, and whether a different company has appeared.
Attachments. Schedules and appendices are often updated separately and forgotten.

When there's no earlier version

If you only have one document, a comparison isn't possible. You can still check that the file itself hasn't been edited since it was produced. A tamper check looks for later saves, editing software in the file's details and text in a different font from the rest, which is how altered figures often show up.

Try it: Document tamper checkSpot signs that a PDF or photo was edited: later saves, editing software, odd fonts and retouched areas.

Scanned contracts

A scanned or photographed contract is a picture of text, so there's nothing for software to compare. Ask for the digital file. If that's impossible, compare the two versions side by side, page by page, paying particular attention to the list above.

If you find a change

Don't assume bad faith. Point it out in writing, quote the clause from both versions and ask which one is intended. Most of the time it's corrected at once. If it isn't, you've learned something important before signing rather than after. For contracts that matter, such as employment, property or large purchases, a lawyer's review is still worth it; a comparison tool shows what changed, not whether a clause is fair.