The reader is where most visits to this site start and end. It opens a document in your own browser, with no upload and no account, and reports what the file actually is - how many pages carry real text, what size the paper is, whether it is encrypted.
The other four tools change presentation rather than content. Cropping and numbering make a document easier to work with; watermarking labels it; comparison tells you what changed between two versions.
Which one do you need?
You just want to read it
PDF Reader opens it immediately with thumbnails, search and a page counter you can type into. The file never leaves your browser - you can disconnect from the network and it still works.
It is uncomfortable to read on a tablet
Crop PDF trims the wasted margin so the text fills the screen. On a document designed for A4 paper, a 20 mm crop roughly doubles the effective text size with no zooming at all.
You are going to print it
Number Pages stamps a number onto each page and writes it into the file. A merged pack without numbers is genuinely unrecoverable if you drop it.
People need to know what this document is
Add Watermark stamps a label such as DRAFT or PRACTICE PAPER across the pages. It is a label, not protection - anyone can crop it off.
You have two versions and need to know what changed
Compare PDF reports every text difference page by page. It is the reliable way to find out what a revised syllabus actually changed.
At a glance
| Tool | Alters content? | Alters appearance? | Reversible |
|---|---|---|---|
| PDF Reader | No | No | n/a |
| Crop PDF | No - content is hidden, not deleted | Yes | Not from the result |
| Number Pages | Adds a number | Yes | No |
| Add Watermark | Adds a label | Yes | No |
| Compare PDF | No | No | n/a |
Before you keep the result
- Cropping hides content, it does not delete it. Never use it to conceal anything sensitive.
- Choose a corner for page numbers that is genuinely empty - exam boards often use the bottom right themselves.
- Check a watermark against the busiest page in the document, not the first one.
- Comparison reads the text layer only. Two scans of the same page cannot be compared.
Questions and answers
Can I highlight or annotate here?
Not in the reader, deliberately. Highlights buried in a PDF are a poor place to keep revision notes, because you have to reopen the file to find them. Extract the text and keep the notes where you actually revise from.
Is my file uploaded when I use the reader?
No. It is opened by your browser from your own disk. Nothing is transmitted. The tools that transform a file do receive it, process it and delete it - the reader does not even do that.
Why does cropping not shrink the file?
Because the content outside the crop is still in it. Cropping changes the page boundary, nothing more.