Words used in a PDF comparison
A PDF comparison reads the text of two versions of the same document and lists every line that was added, removed or edited, with the page it sits on: for example, if a client sends back a 3-page contract where only the fee on page 2 moved from $6,000 to $6,800 (example), the result is one edited line on p. 2 with the old and new figure marked.
The tool compares words, not pixels. These terms explain what you see in the result, and why a change can show on a different page in V1 and V2.
- V1 and V2
- V1 is the PDF your client reviewed in the last round, or the one they signed. V2 is the new export you are about to send, or the copy they sent back. Every change is described as going from V1 to V2.
- Text layer
- The real, selectable text inside a PDF. Files exported from a layout, word or slide app have one. A scan or a PDF saved as pictures does not, so there is nothing to compare in words.
- Edited line
- A line that exists in both versions but with some words changed. The removed words are struck through in red and the new words are marked in green, so a changed price or date stands out inside the sentence.
- Removed and added lines
- A line found only in V1 was removed; a line found only in V2 was added. A whole new page in V2 shows as a block of added lines on that page.
- Page reference
- Where a line sits, such as “p. 2” when it is on the same page in both files, or “V1 p. 4 → V2 p. 5” when the text moved because something earlier grew longer.
- Context lines
- Unchanged lines shown above and below each change, so you can tell which clause or section it belongs to without opening the PDF. Set it to 0 to see only the changes.
Sample PDF versions compared
These are made-up documents, not real client files. Each row runs the same text through the same comparison as the tool above, so you can see how page numbers are reported when a page is added, a paragraph is cut, or text moves to a later page.
| Example | Pages (V1 → V2) | Lines edited | Lines removed | Lines added | Pages with changes |
|---|---|---|---|---|---|
| Example: contract, fee changed on page 2 | 3 → 3 | 1 | 0 | 0 | V1 2 · V2 2 |
| Example: brochure, a page added | 3 → 4 | 0 | 0 | 3 | V1 none · V2 3 |
| Example: report, a paragraph cut | 1 → 1 | 0 | 1 | 0 | V1 1 · V2 none |
| Example: proposal, dates moved to a later page | 2 → 2 | 0 | 1 | 1 | V1 1 · V2 2 |
| Example: price list, typo fixed on page 1 | 2 → 2 | 1 | 0 | 0 | V1 1 · V2 1 |
| Example: same PDF exported twice | 2 → 2 | 0 | 0 | 0 | None |
What a PDF text comparison can miss
A PDF comparison ignores layout and images
A new photo, a colour change, a moved logo or a different font will not show up, because only the words are compared. For visual changes, export both pages as images and use the image comparison tool, which marks every changed pixel.
Reading order can differ between exports
Some apps store columns, text boxes or tables out of reading order. If two exports place a sidebar differently, a few lines can show as removed and added even though nothing changed. Check those blocks by eye.
Moved text shows as removed and added
When a paragraph moves from page 2 to page 6, the tool sees it disappear in one place and appear in another. That is correct, but it can look larger than the real edit. Read the two blocks side by side before you tell a client something was rewritten.
Scanned or flattened PDFs have no text to compare
If a client prints, signs and scans a contract, the returned PDF is a picture. The tool tells you when a file has no text layer. Compare the scan with the original as images instead, or ask for the editable file.
A clean result is not a legal review
The tool shows differences in text. It does not judge what a changed clause means. For contracts, read every flagged line yourself and ask someone qualified when a change matters.
Questions about comparing two PDF files
Are my PDF files uploaded when I compare them?
No. Both files are opened inside this browser tab, the text is read page by page on your device, and the comparison runs there too. Nothing is sent to TweakTick or anyone else, which matters for contracts and unreleased work.
How do I find what a client changed in a PDF they sent back?
Add the PDF you sent as V1 and the returned copy as V2. The summary says how many lines were edited, removed and added, and the page list jumps straight to each one. Copy the change list to reply with exact page numbers.
Why does the PDF comparison say a line moved pages?
If something near the start of the document got longer, every line after it can be pushed down onto the next page. The text is still the same, so it is not counted as a change, but its page reference shows both page numbers when it is part of a change.
Can the PDF compare tool ignore capitals and spacing?
Yes. Tick “Ignore capitals” to treat “Book A Table” and “Book a table” as the same, and “Ignore extra spaces” to skip double spaces and stray spaces at line ends. Both settings also apply to the copied change list.
Is there a page limit for comparing two PDFs?
Each file can be up to 100 MB and 600 pages. Very long documents take a moment on a phone. For a larger file, split it and compare the parts one by one.
Should I compare pasted text or the PDF itself?
Use this tool when you have two PDF files and want page numbers. When the copy lives in an email, a document or a website, paste both versions into the diff checker instead; it is faster and shows word changes the same way.
Can I save the result of a PDF comparison?
Yes. “Copy change list” puts a plain-text list on your clipboard, with each change marked by its page, ready for an email or a ticket. “Download .txt” saves the same list as a file you can attach to the project.