Blur PDF Online — obscure text, faces, or images with the blur baked into the page
Draw a box over anything you want blurred, or blur whole pages at once. Blurred pages are flattened into an image with the effect applied directly to the pixels — there's no separate layer to peel back.
Blur is not the same guarantee as redaction. Redaction replaces content with a solid fill — nothing is left behind. Blur reduces legibility, but at low intensity, short or predictable text can sometimes be partially reconstructed. For content that must never be recoverable, use Redact PDF instead.
The blur console
Upload a PDF, draw boxes or pick full-page blur, then apply.
Blur reduces legibility — it doesn't erase information
The effect is baked directly into the page's pixels, so there's no overlay to remove. But blur is a lossy transformation, not a zero-information one — for anything that must be completely unrecoverable, use Redact PDF instead, which replaces content with a solid fill.
Drop your PDF here
or browse files
PDF page preview. Use the page navigation controls to change pages. In area mode, draw a blur region over the content you want to obscure.
Click and drag on the page above to draw a blur box.
2. Blur intensity
Higher values reduce legibility further — use a higher setting for anything sensitive.
3. Blur areas on this page
No blur areas on this page yet.
Blur and redaction solve different problems
Both obscure content on a page. Only one of them guarantees the original is actually gone. Picking the wrong one for a sensitive document is an easy, avoidable mistake.
Blur — softens, doesn't erase
Blur applies a genuine Gaussian blur to the pixels in a region, baked directly into a flattened image — there's no separate layer sitting on top that could be peeled away.
But blur is a lossy transformation, not a zero-information one. At low or moderate intensity, especially for short, predictable text like a phone number or a code, some information can survive well enough for deblurring techniques or careful guessing to partially recover it. Use blur for softening a face, a background detail, or content where reduced legibility is genuinely enough.
Redaction — replaces, doesn't just obscure
Redaction fills the selected area with a solid color, then flattens the page the same way blur does. The difference is what's being flattened: a solid fill has no underlying pattern or structure left to reconstruct.
Use Redact PDF for anything that genuinely must never be recoverable: legal documents, medical records, financial data, or personal identifiers. When in doubt, redaction is the safer default.
Draw, set intensity, then apply
Everything is adjustable until you finalize — after that, it's permanent.
Upload your PDF
Drag it onto the upload area, or click Select PDF. The first page loads into the blur console right away.
Choose mode and intensity
Pick how you want to blur, then set how strong:
Choose which pages
Apply the current settings to just this page, all pages, or a specific range you type in.
Apply and download
Click Apply & Finalize. Blurred pages are flattened with the effect baked in, then the file is ready.
What blur is genuinely good for
Reduced legibility is the right amount of protection for some content, and not enough for other content.
| Use case | Why | Right tool |
|---|---|---|
| Softening a face in a photo | Reduced recognizability is usually the actual goal, not total erasure of every pixel. | Blur |
| De-emphasizing a background detail | Drawing attention away from a distracting or minor element in a scanned document. | Blur |
| Draft watermarking or previews | Making a preview unusable without obscuring that it exists, e.g. a sample page. | Blur |
| Social Security or account numbers | Short, predictable strings are exactly the content most at risk from deblurring attempts. | Redact instead |
| Legal or medical records | Genuinely confidential information where any residual recoverability is unacceptable. | Redact instead |
| Official disclosures & public records | When information requires reliable removal, use a verified redaction workflow instead. | Redact instead |
How the blur gets baked into the page
The literal sequence of steps that turns your boxes and intensity setting into a finished file.
Render each selected page to a canvas
Every page you've chosen to apply blur to is rendered fresh at high resolution, the same pipeline used for the on-screen preview.
Apply the blur filter to the pixels
For full-page mode, a Gaussian blur is applied to the entire rendered image. For area mode, a separately blurred copy of the page is clipped to just your drawn boxes and painted over the sharp version — only inside those regions.
Encode the result as a flattened image
The canvas — now containing the blur, baked directly into its pixels — is exported as a JPEG. The sharp version isn't retained anywhere in this process.
Replace the page with that image
The flattened image becomes the entire content of a new page in the output PDF, so there's no separate blur layer sitting on top of untouched text underneath.
Leave untouched pages as they were
Pages you didn't select keep their original text and vector content, so they stay searchable and don't unnecessarily grow in file size.
When something doesn't look right
What's actually happening, and the fastest way through it.
Blurred text still looks somewhat readable
The intensity was set too low for how sensitive the content is.
Increase the intensity slider, or switch to Redact PDF if the content must be completely unrecoverable.
Output file is noticeably larger
Pages with blur applied become images, which are typically larger than the original text or vector content.
Run the result through Compress PDF afterward if size matters.
Text on unblurred pages is no longer selectable
Pages you didn't select for blurring keep their original text — if the whole file looks flattened, double-check what "Apply to Pages" was set to.
Only pages actually selected are flattened; re-check your page selection before applying.
A password-protected PDF won't load
Encrypted files can't be read by the in-browser rendering engine.
Remove the password with a PDF unlock tool first, then upload the unlocked copy.
Apply button does nothing
No PDF has been uploaded yet.
Upload a PDF first — the button becomes active once pages have loaded.
Blurred text still readable
Why: Intensity too low.
Fix: Increase it, or use Redact instead.
File size larger
Why: Blurred pages become images.
Fix: Compress afterward.
Unblurred text not selectable
Why: Check "Apply to Pages" selection.
Fix: Re-check before applying.
Password-protected PDF won't load
Why: Encrypted files can't decode in-browser.
Fix: Unlock it first, then upload.
Apply button does nothing
Why: No PDF uploaded.
Fix: Upload a PDF first.
Blurring with the right amount of caution
A working approach that matches intensity to what's actually at stake.
Ask what's actually at stake first
If the content being obscured would cause real harm if recovered, use Redact PDF instead — don't reach for blur by default.
Use higher intensity than feels necessary
A blur that looks "obscured enough" to the eye can still leave more structure than you'd expect — err on the stronger side.
Cover generously, not exactly
Draw boxes slightly larger than the content itself — a tight box that clips an edge can leave a readable fragment.
Review every page before finalizing
Page through the whole document once more — it's much easier to add a missed box now than after downloading.
Keep the original file separately
Blurring is one-way by design — keep your unaltered source somewhere safe in case you need a different version later.
When in doubt, redact instead
If you're unsure whether blur is strong enough for your situation, that uncertainty is itself a reason to use the stronger guarantee.
PDF blur FAQs
Start with the first question if you're weighing whether blur is strong enough for your situation.
Is blur as secure as redaction?
No, and it shouldn't be treated that way. Redaction replaces content with a solid fill, leaving zero information behind. Blur is a lossy transformation, not a zero-information one — at low or moderate intensity, blurred text (especially short, predictable strings like numbers or codes) can sometimes be partially reconstructed with deblurring techniques. For content that must never be recoverable, use our Redact PDF tool instead. Use blur when reduced legibility is genuinely enough, such as softening a face or a background detail.
Is the blur baked into the file, or just an overlay I could remove?
It's baked in. Any page you blur is rendered to an image with the blur applied directly to the pixels before that image is placed in the output PDF. There is no separate overlay layer to peel back — the sharp version of that region is not included in the file.
Will pages I don't blur also become images?
No. Only pages you actually apply blur to are flattened into an image. Pages left alone keep their original text, formatting, and searchability.
Is it safe to upload my documents here?
Yes. The entire process happens locally in your browser — your files are never uploaded to a server.
Can I undo a blur before finalizing?
Yes. You can move, resize, or delete any blur box, and change the intensity or mode, at any point before clicking Apply & Finalize. Once you finalize and download the file, the change is permanent and cannot be undone from within this tool.
The write-up on how this was built
Because getting the blur-vs-redaction distinction right matters, I wrote up the implementation in detail — how the blur is baked into flattened pixels, and why blur intensity should scale with how sensitive the content actually is.
Blur vs Redaction: What Each One Actually Guarantees
Covers Gaussian blur as a lossy transformation, real-world deblurring techniques, and why solid-fill redaction is the stronger guarantee for genuinely sensitive content.