Leases, employment contracts and quotations often go back and forth several times. When the "latest version" arrives, the question is: was only what we agreed changed? Reading both line by line is tiring and easy to get wrong. Here's how to find the changes, depending on the file you receive.
Why compare before signing
The Bank of Thailand warns never to sign without reading and understanding the contract's terms, and to be sure you accept the conditions before you sign.
Thailand's Office of the Consumer Protection Board (OCPB) advises checking that the contract's wording is precise and gives you every right agreed in the negotiation, and that any agreement you want to be binding is made in writing.
After several rounds of edits, a number or condition you never discussed can change without anyone noticing, so comparing the old and new versions helps a lot.
A Word file: use Compare, or ask for Track Changes
Ask the other side to turn on Track Changes before editing: on the Review tab, select Tracking > Track Changes. Microsoft explains that deletions are struck through, additions are underlined, and each author's changes appear in a different colour.
If they didn't use Track Changes, use Compare: on the Review tab, select Compare, then compare two versions of a document (legal blackline), and choose the original and the revised file. Word creates a third document showing the differences as tracked changes, leaving both originals untouched.
A Google Docs file: use Compare documents
Google suggests this feature specifically for contract negotiations. Choose Tools > Compare documents and pick the other Google Doc; the differences appear as "Suggested edits" in a new document. You need to own the document or have edit access.
A PDF: use a PDF compare tool
Contracts often arrive as PDFs, which have no Track Changes to look at. Adobe Acrobat has a Compare files command in Acrobat Pro.
Another way is our free PDF compare tool. It runs in your browser and your files are never uploaded — a good fit for contracts with personal details.
- Choose the original and the new version.
- It compares word by word (Thai included) and tells you how many differences there are.
- Removed words are red, added words green; click a change and both documents jump to that spot.
- Download both PDFs highlighted, plus a list of every change — keep them as a record or send them to your lawyer.
If the contract is a scan, which is a picture, run OCR first so it has text, then compare — and check the important numbers by eye, since OCR can misread.
Checklist: what to read closely
A tool shows which words changed; what they mean is up to you. Read these carefully every time something changes:
- Money: rent, price, deposit, security deposit, penalties.
- Dates and periods: payment deadlines, start and end dates, notice periods.
- Small words that change the meaning: "must" vs "may", "not more than" vs "not less than", "and" vs "or".
- Whole clauses removed, especially ones that give you rights.
- Names, addresses and registration numbers of the parties and the property.
After signing
The OCPB says the business must deliver the contract to the consumer, and advises that the parties and witnesses sign in each other's presence. Keep the signed copy together with the highlighted comparison — it helps a great deal if there is a dispute later.
To sign a PDF contract yourself, use Sign PDF without uploading the file.
Note
This article is based on help pages from Microsoft, Google and Adobe and documents from the Bank of Thailand and the OCPB, read on 29 September 2026. Menu names can differ between versions. This is general information, not legal advice; have a lawyer review high-value contracts before signing.
