Browser-based PDF redaction tools compared
Five tools that redact a PDF from a web page, compared on the things that actually differ: where your file is processed, what the free tier gets you, and whether the hidden text is really gone. One of them is ours, and it is marked as ours.
Checked August 4, 2026. Every claim below is what the tool says on its own page, linked in the last column. We have not tested other vendors' software and we do not report our own results as theirs.
| PDFRedax ours | Xodo | Smallpdf | PDF24 | iLovePDF | |
|---|---|---|---|---|---|
| Where the file is processed | In your browser | In your browser | In your browser | Uploaded to their servers | Not stated |
| Free tier | 1 page | 1 document/day | Yes, limits unstated | Yes, ad-supported | Not stated |
| Account needed | No | No | No | No | Not stated |
| The hidden text | Text deleted | Permanent, they say | Permanent, they say | Pages rasterised | Not stated |
| Scanned pages (OCR) | Yes, on your device | Not stated | Not stated | Not stated | Not stated |
| Source | our verification page | xodo.com/redact-pdf | smallpdf.com/redact-pdf | tools.pdf24.org | ilovepdf.com/redact-pdf |
What each one says, in its own words
PDFRedax (ours)
We rebuild redacted pages without the underlying text, so there is nothing left to copy, and we publish the steps to confirm the file never leaves your device. After the free first page it is a one-time charge by page count: $5 up to 10 pages, $10 up to 25, $30 up to 100. No subscription, no account. our verification page, checked August 4, 2026.
Xodo
"Redaction is done directly in your browser without having to upload your files to external servers." Their FAQ says one document a day can be redacted free without registration, that the information "cannot be retrieved or viewed by anyone", and that the action "is permanent and cannot be undone". xodo.com/redact-pdf, checked August 4, 2026.
Smallpdf
"Process files 100% in your browser. Your documents download directly to your device and nothing is stored on our servers." They say "true redaction completely eliminates the data from your document" and that the tool "doesn't just hide it visually". The free tier has "some usage limits" that the page does not quantify. smallpdf.com/redact-pdf, checked August 4, 2026.
PDF24
"This app runs on our servers in the cloud and your system is not changed." Files "are automatically deleted from the PDF24 server after one hour". Redaction converts affected pages to raster images, which they say means the information "can no longer be restored — not even with special tools or through technical analysis". tools.pdf24.org, checked August 4, 2026.
iLovePDF
Their redaction page makes none of these claims either way: it does not say where the file is processed, whether an account is needed, what the free limits are, or whether the hidden text is removed. What it does say is "Remember to review the result of your document before sending private information." That is good advice, and it is the whole basis for this row. ilovepdf.com/redact-pdf, checked August 4, 2026.
What the table does not tell you
Four of these five say the work happens in your browser. That is a claim, not a property you can see, and every one of them is asking you to take their word for it. The difference that matters is whether you can check.
You can, in about ten seconds, and it works on any of these tools. Open your browser's developer tools, switch to the Network tab, then load your document and redact it. If the file is being processed locally, nothing leaves. The harder version of the same test: disconnect from the internet and try to redact anyway. A tool that runs on your machine will not notice.
We publish those steps for our own tool on the verification page, because a privacy claim you cannot check is just marketing — including ours.
The other half of the problem
Choosing the tool is the easy part. The failure that actually leaks documents is not picking the wrong vendor, it is covering text with a black box and believing that removed it. The box is drawn on top of the page; the words stay underneath, and anyone can select and copy them.
We measured how often this reaches the public record. In a study of 5,987 public U.S. federal court filings, 1,879 had been redacted with black boxes and 22 of those still had the hidden text sitting underneath — among them the name of a cooperating witness in a federal drug prosecution. Whichever tool you pick from the table, check the output before you send it.
What we would actually tell you to use
If the document is confidential and you need to be able to prove it never left your computer — a client file, medical records, anything under a legal or professional duty — use a tool that publishes a way to verify it, and then run the verification. That is the case we built PDFRedax for, and it is the only claim on this page we would defend as a real difference.
If you just need one ordinary document blacked out now and then, Xodo's one-free-document-a-day and Smallpdf's free tier both say they run in your browser and both cost nothing. There is no reason to pay us for that.
If you need a lot of pages for free and the content is not sensitive, PDF24 has no page limit — but it uploads your file to their servers, so do not use it for anything you would not email to a stranger.
If you are redacting a court filing, none of this is optional: check the exported file by hand before you file it.
Questions
- Which browser-based PDF redaction tool should I use?
- If you need to prove the document never left your computer, use a tool that publishes a way to check — open the browser network tab, or disconnect from the internet and redact anyway. If you just need one document blacked out occasionally, the free tiers of Xodo and Smallpdf both say they run in your browser. If you need a lot of pages for free and the document is not confidential, PDF24 is free without limits, but it uploads your file to their servers.
- Is a tool that runs in the browser automatically private?
- No. Running in the browser means the file does not have to be uploaded, but you are still taking the vendor at their word unless you can check. The check takes ten seconds: open your browser's network tab before you redact, and watch whether the file goes out. A tool that is genuinely local will also work with your internet disconnected.
- Does covering text with a black box redact it?
- No. The box is drawn on top; the text stays in the file underneath and can be selected and copied. In our study of public U.S. federal court filings, 22 filings that had been redacted with black boxes still had the hidden text recoverable underneath.
- How do I check that a redaction actually worked?
- Open the redacted file, try to select the line the black box sits on, copy it, and paste it into a text editor. If the hidden words appear, the redaction failed. Searching the file for a word you removed is a second check.
Corrections welcome. If we have described your tool wrongly, or your page has changed since August 4, 2026, email help@pdfredax.com and we will fix it and say that we did.