What this covers
- Transforming a file requires having it - there is no way around that
- A reader that renders in the browser genuinely does not upload
- Retention, logging and third-party scripts are the things to check
- For confidential material, local software is the correct answer
This is a question we get asked about our own site, and the honest answer is not a straightforward yes. It depends on what the document is, and for a meaningful category of documents the answer is that you should not use any online tool, including this one.
What an online tool necessarily does
To merge two PDFs, a server has to have both of them. To compress a document it has to decode its images. There is no cryptographic trick that lets a remote machine transform a file it cannot read.
So any site offering these operations receives your file. The question is never whether it receives it - it is what happens next, and for how long.
A reader is different
Rendering a PDF for display can be done entirely in your browser, and on this site it is. The reader reads the file from your own disk into your own memory and never transmits it. You can verify that by disconnecting from the network and opening a document - it still works. That is a genuinely different situation from a tool, and it is worth knowing which you are using.
What to ask of any service
Five questions, and a service that cannot answer them clearly has answered them.
The five questions
And what this site's answers are.
| Question | Why it matters | This site |
|---|---|---|
| How long are files kept? | Retention is the main exposure | 30 minutes maximum, usually seconds |
| Are files logged or indexed? | A deleted file in a log is not deleted | No file contents or names are logged |
| Is there an account? | An account links files to a person | No accounts exist |
| Are there third-party scripts? | They see the page and sometimes more | None, enforced by a strict content policy |
| Who runs it? | An anonymous service is an unaccountable one | Named, on the editorial policy page |
Where the line sits
For a past paper downloaded from an exam board's public website, the question is close to meaningless. The document is public; there is nothing to expose.
For a marked script with your name on it, it is a real question with a defensible answer either way. For medical records, legal documents, anything under a professional duty of confidence, or anything covered by an employer's data policy, the answer is no - and not because of any particular site's practices, but because the category of action is wrong.
When online is fine and when it is not
Decided by the document, not by the tool.
Online is fine
- Public documents - past papers, published guides
- Your own notes and revision material
- Coursework you are about to submit anyway
- Anything you would be comfortable emailing
Use local software
- Medical, legal or financial records
- Anything under a professional duty of confidence
- Anything covered by an employer's data policy
- Anything you would not email to a colleague
What local software means
Not a subscription. Every current operating system can combine, split, rotate and print PDFs without any additional software, and free, open, offline applications cover compression, form filling and more.
It is slightly less convenient and it is the right answer for a confidential document. We would rather say so than talk you into using a website because it happens to be ours.
What this site does with a file
The uploaded file is written to a temporary directory, processed, and the result written next to it. A sweeper runs on every request and removes any job older than thirty minutes; in practice most jobs are gone within seconds of the download, because the next visitor's request triggers the sweep.
No file contents or filenames are logged. There are no accounts, so nothing links a file to a person. Passwords supplied to open or protect a document exist in memory for that one operation and are never written anywhere. There are no third-party scripts on any page, which is enforced by a content security policy rather than by intention.
Tools on this site
Before uploading anything anywhere
- Ask what the document actually is, and who would be harmed if it leaked
- Check whether the operation can be done locally instead
- Read the service's retention statement, and whether it is specific
- Check whether there is an account, and avoid creating one if there is a choice
- Remove what you can before uploading - redact first, then process
- For anything confidential, do not upload it at all
Questions and answers
Does this site keep my files?
No. Uploads and results are deleted within thirty minutes and usually within seconds of the download. The reader does not upload anything at all - it renders in your browser.
Can I use an online tool for work documents?
For ordinary documents, generally yes. For anything confidential or covered by an employer's policy, no - use local software. Any online tool has to receive the file, and that is true here as everywhere.
How would I verify that a site does what it claims?
You largely cannot, which is why the question of who runs it matters. A named team with a specific retention statement is more accountable than an anonymous service with a vague one, and neither is a proof.
Is the reader on this site really not uploading anything?
Yes, and you can check. Open the reader, disconnect from the network, and open a document. If it renders, nothing was transmitted.
