Calculator
What the Compare PDF does
Compare PDF: extracts the text of both documents page by page and reports which pages match, which differ and what changed on each. Everything runs in your browser and the file is never uploaded.
The Compare PDF works on a file you choose, without sending it anywhere. Everything runs on your own device, which means no waiting and no copy left on a server.
Typical users are anyone tidying a scanned document. A quick page edit should not require installing desktop software.
No upload means no copy of your document sitting on somebody else’s server.
The meaning of each field, the formula in use, and a worked example that starts from the default inputs are all further down.
What do the Compare PDF fields mean?
The Compare PDF uses 3 inputs. You can work from the defaults, or clear them and start fresh, both work.
| Field | What to enter | Default |
|---|---|---|
| Original PDF (A) | stays on your device | none |
| Revised PDF (B) | stays on your device | none |
| Ignore whitespace differences | choose from Yes or No | Yes |
How does the Compare PDF work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same calculation.
Checks happen up front, so errors surface next to the form instead of hiding in the output.
What a typical run looks like
You provide: Original PDF (A), Revised PDF (B) and Ignore whitespace differences
What happens: the file is read into memory by your browser, processed locally, and offered back as a download. It is never uploaded.
You get back: a processed file plus a short status summary in the tool panel.
The tab does the processing, so speed tracks your hardware and very large files fail on memory rather than on a quota.
How to use it
- Choose your file under Original PDF (A), or drag it onto the drop area.
- Choose your file under Revised PDF (B), or drag it onto the drop area.
- Pick a value for Ignore whitespace differences: the options are Yes or No.
- Press Compare.
- You get Status, Pages Changed, Pages Identical, Pages in A and Pages in B back.
- Copy Link is the quickest way to send the exact scenario to someone else.
What this tool does not do
- Very large documents are limited by your device's available memory, not by a server quota.
- Encrypted or password-protected files must be unlocked before they can be processed.
- Defaults are illustrative starting points, not recommendations.
- Performance scales with your own hardware, since no server does the work.
Frequently asked questions
3 things: Original PDF (A), Revised PDF (B) and Ignore whitespace differences. Nothing starts empty, meaning you can explore the calculation before committing to real figures.
It is not uploaded. Everything happens on your device, so no copy of your file exists on any server.
Nothing at all. There is no registration, no paywall and no per-use quota.
It implements the published definition directly, without shortcuts or approximations.