How to Compare Two Versions of a Contract (PDF)

1. 1

   Gather both files

   Have the older version and the newer version as PDFs with selectable text.

2. 2

   Run a text comparison

   Upload them as A (original) and B (revised) in a compare tool.

3. 3

   Read the added and removed words

   Go through every flagged change, page by page.

4. 4

   Check what text cannot show

   Look separately at images, signatures, layout and any scanned pages.

When two drafts look almost identical, your brain fills in what it expects to see. A date moved by a week, "may" swapped for "shall", or an amount changed from 15 to 30 can sit inside a paragraph that otherwise reads the same. Reading both documents side by side takes a long time and the small edits are exactly the ones that slip through.

Counterparties sometimes send a clean PDF instead of a redline, which leaves you to work out the differences yourself. Even with good intentions, someone may have touched a clause that was supposed to be settled. A systematic comparison gives you a list to review rather than relying on attention alone.

The Compare PDF tool reads the selectable text from every page of both files and compares it word by word. It runs in your browser, so for this tool the files stay on your device rather than being uploaded.

1. 1

   Open the tool

   Go to the Compare PDF page and add the original as file A and the revised document as file B. Using the older one as A keeps "added" and "removed" meaningful.

2. 2

   Choose matching options

   You can ignore capitalisation and punctuation if you only care about real wording changes. Leave them off for a contract where a comma or capital letter might matter.

3. 3

   Click compare

   The tool reads each page and builds a summary on screen.

4. 4

   Review and download the report

   Added words appear in green and removed words in red, per page. You can download the full report as a PDF to share with colleagues.

A word-level text comparison is good at changed wording, numbers, names, dates, and added or deleted sentences. It compares the text itself, not how the page looks.

• Caught: edited figures, replaced words, new or deleted clauses, changed party names.
• Not caught: a changed logo, a different image, a signature, a stamp, or a chart.
• Not caught: layout, fonts, colours, bold or italic emphasis, and margin changes.
• Scanned pages: they contain a picture, not text, so there is nothing to compare until you run OCR.
• Moved text: because pages are compared by number, a paragraph that shifts to the next page shows as removed on one page and added on another, even though the wording is the same.
• Different page counts: pages that exist in only one file are reported as missing from the other.

Treat the report as a pointer to where to look, not proof that nothing else changed.

Start with the page summary to see where the changes cluster. A handful of small edits is usual in a round of negotiation; a whole page marked as changed often means text was reflowed or moved rather than rewritten.

For each red and green pair, open both PDFs to the same page and read the full sentence. A removed word can look harmless in isolation but alter the meaning of a clause, such as "not" disappearing. Pay particular attention to numbers, dates, deadlines, payment terms, liability limits and defined terms.

If a page looks heavily changed because content shifted, read the neighbouring pages too, since the same text may simply have moved. Make a short list of the changes you need to raise with the other party.

• Ask for the editable source when possible. A Word compare or tracked changes from the original file is more complete than comparing exported PDFs.
• Run OCR first on any scanned page so it has text. Our OCR PDF tool is a paid feature, so check your plan.
• Look at images, signature blocks and headers or footers by eye after the text check.
• Check that the page count matches and that appendices or schedules were not dropped.
• Confirm file names and dates so you know which PDF really is the latest.
• Keep the original and the report together so you have a record of what you reviewed.

This guide is not legal advice. For anything binding, have a qualified person review the final text and do not rely on a comparison tool alone.

Two PDFs of the same contract can differ in ways that have nothing to do with the wording. One may have been exported from Word and the other printed to PDF from a different program, or one may have been scanned and re-saved. Differences in hyphenation, line breaks and headers can produce noise in the report even when the clauses are identical. If the report looks far longer than you expect, check whether the text is being read in a different order, for instance because of columns or text boxes.

In that case, ask the sender for a fresh export from the same source document, or compare only the sections you care about. When a handful of pages are noisy, review those by eye and rely on the tool for the rest. A comparison is most useful when both files came from the same editable source and only the content changed.

It also helps to agree on a routine with the other side: label each file with a version number and date, send the editable file along with the PDF, and keep a short list of the sections each round was meant to change. Then any change outside that list stands out immediately in the report.