How to Redact a PDF Online: Complete Step-by-Step Guide

You have a PDF with sensitive information that needs to be removed. You do not have Adobe Acrobat Pro installed. You do not want to download and install desktop software. You just want to upload your PDF, redact it, and download the result.

Online PDF redaction tools make this possible. Browser-based tools let you redact PDFs from any device — Windows, Mac, Linux, Chromebook, or even a tablet — without installing anything.

This guide walks you through how to redact a PDF online, which tools to use, and what security considerations matter when uploading sensitive documents to a web-based service.

How to Redact a PDF Online with AI-Redact

AI-Redact is the only online redaction tool with AI-powered detection that automatically finds sensitive information in your PDF. Here is the step-by-step process.

Step 1: Open the Tool

Go to ai-redact.com/tool. No account creation or signup is required for the free tier.

Step 2: Upload Your PDF

Click the upload area or drag and drop your PDF file. The tool accepts PDF files up to the size limits of your tier (free tier handles standard documents).

Step 3: AI Detection

Once uploaded, AI-Redact's machine learning models automatically scan your document for sensitive information. The AI detects 40+ data types including:

Names (person names, patient names)
Social Security numbers
Credit card numbers
Bank account numbers
Phone numbers
Email addresses
Physical addresses
Dates of birth
Medical record numbers
Driver's license numbers
Passport numbers

For scanned PDFs (paper documents digitized as images), OCR automatically extracts text before detection runs.

Step 4: Review Detections

The tool presents every detection for your review. Each item is highlighted in the document with its category labeled. You can:

Confirm detections that should be redacted
Reject false positives (items the AI flagged that you want to keep)
Manually add items the AI missed by selecting text in the document

This review step ensures you maintain full control over what gets redacted. The AI handles the tedious detection; you make the decisions.

Step 5: Apply Redaction

Once you have finalized your selections, apply the redaction. The tool permanently removes the selected text from the PDF content stream — this is true redaction, not a visual overlay. The text data is deleted, metadata is scrubbed, and the redacted areas are marked with visual indicators.

Step 6: Download

Download your redacted PDF. The file is ready to share, with all selected sensitive information permanently and irreversibly removed.

The entire process typically takes 2-5 minutes depending on document length, compared to 30-60 minutes for manual redaction.

Alternative Online PDF Redaction Tools

Smallpdf

Website: smallpdf.com Free limit: 2 tasks per day AI detection: No

Smallpdf offers a manual redaction tool as part of its broader PDF toolkit. You select text or draw boxes over areas to redact. The tool performs permanent redaction but requires you to manually identify every piece of sensitive information.

How to use: Upload PDF → Manually select text or draw boxes → Apply → Download

Best for: Users who already use Smallpdf for other PDF tasks and need occasional simple redaction.

iLovePDF

Website: ilovepdf.com Free limit: Limited AI detection: No

iLovePDF provides basic manual redaction — draw boxes or select text to redact. Permanent redaction is applied. No AI detection or OCR.

How to use: Upload PDF → Draw boxes over sensitive areas → Apply → Download

Best for: Basic, occasional redaction of simple documents.

PDF24

Website: tools.pdf24.org Free limit: Unlimited AI detection: No

PDF24 offers area-based redaction with no document limits. You draw rectangles over areas to redact. The tool removes content in the selected areas.

How to use: Upload PDF → Draw rectangles over areas → Apply → Download

Best for: Budget-conscious users who need unlimited free redaction and are willing to do all identification manually.

AvePDF

Website: avepdf.com Free limit: Limited (file size restrictions) AI detection: No

AvePDF provides manual text selection and area redaction in a clean interface.

How to use: Upload PDF → Select text or areas → Apply → Download

Best for: Simple, occasional redaction needs.

Online Tools Comparison

Feature	AI-Redact	Smallpdf	iLovePDF	PDF24	AvePDF
AI Detection	Yes (40+ types)	No	No	No	No
OCR (Scanned PDFs)	Yes	Paid only	No	No	No
Permanent Redaction	Yes	Yes	Yes	Yes	Yes
Metadata Scrubbing	Yes	Limited	No	No	No
Free Tier	5 docs/month	2/day	Limited	Unlimited	Limited
SOC 2 Certified	Yes	Yes	No	No	No
HIPAA Compliant	Yes	No	No	No	No
Zero Data Retention	Yes	Varies	Varies	Varies	Varies
Avg. Time (10 pages)	2-3 min	20-30 min	20-30 min	20-30 min	20-30 min

Security Considerations for Online Redaction

When you redact a PDF online, you are uploading a document containing sensitive information to a third-party server. Before doing this, consider the following.

Where Do Your Files Go?

Every online tool uploads your document to their servers for processing. The document travels over the internet and is stored (at least temporarily) on the tool's infrastructure. For sensitive documents, understand:

Server location: Where are the servers? Some regulations require data to remain in specific jurisdictions.
Who has access: Can the tool's employees access your documents?
Processing: Is processing done on the server or partially in the browser?

How Long Are Files Retained?

This is the most important security question. Tools handle retention differently:

Zero retention: Files are deleted immediately after processing (most secure)
Temporary retention: Files are deleted after hours or days
Indefinite retention: Files are stored until you delete them
Unclear: The policy does not specify

AI-Redact follows a zero data retention policy — files are deleted after processing. Always verify the retention policy for any online tool you use with sensitive documents.

Is the Connection Encrypted?

The upload and download must use TLS/SSL encryption (HTTPS). Verify that the tool uses HTTPS — look for the lock icon in your browser's address bar. Without encryption, your document could be intercepted in transit.

Does the Tool Have Security Certifications?

Independent security audits provide verification that a tool meets established security standards:

SOC 2 Type II: Comprehensive audit of security, availability, processing integrity, confidentiality, and privacy controls
HIPAA compliance: Required if you handle Protected Health Information
ISO 27001: International standard for information security management

What Type of Document Are You Redacting?

The appropriate level of security depends on the document:

Low sensitivity (personal letter, social media post): Any reputable online tool is fine
Medium sensitivity (business contract, resume): Use a tool with encryption and reasonable retention policies
High sensitivity (medical records, financial data, legal documents): Use a tool with SOC 2 certification, zero data retention, and HIPAA compliance if applicable

When to Use Online vs. Desktop Redaction

Use Online Tools When

You do not want to install software
You are working from a device where you cannot install applications (Chromebook, shared computer)
You need a quick one-time redaction
The document sensitivity is appropriate for the tool's security posture
You want AI-powered detection (only available in online tools for most users)

Use Desktop Tools When

You cannot upload documents to external servers due to policy or regulation
You work in an air-gapped environment
You process classified documents
Your organization's security policy prohibits online processing
You need full offline capability

Desktop Options

Adobe Acrobat Pro ($22.99/month): Full-featured desktop PDF editor with dedicated redaction tools
Mac Preview (Free, Mac only): Basic but functional manual redaction built into macOS

Tips for Redacting PDFs Online

Tip 1: Use AI Detection

Manual redaction online is no different from manual redaction in desktop software — you still have to find everything yourself. The primary advantage of online tools is access to AI-powered detection that does the finding for you. Use a tool with AI detection to save time and reduce the risk of missing something.

Tip 2: Review Before Applying

AI detection is not perfect. Always review the detections before applying redaction. Confirm each item, reject false positives, and manually add anything the AI missed. Once redaction is applied, it is permanent and irreversible.

Tip 3: Keep the Original

Never overwrite your original file. Download the redacted version as a new file. If you need to create a differently redacted version later (for a different recipient or purpose), you will need the original.

Tip 4: Verify the Result

After downloading the redacted PDF, open it and verify:

Try selecting text in redacted areas — nothing should be selectable
Copy and paste from the page — no redacted content should appear
Search for terms you know were redacted — nothing should be found

Tip 5: Check Metadata

Some online tools scrub document metadata automatically; others do not. After redaction, check the document properties for sensitive information in the author, title, subject, or comments fields.

Frequently Asked Questions

Can I redact a PDF online for free?

Yes. AI-Redact offers a free tier with AI-powered detection for 5 documents per month. PDF24 offers unlimited free manual redaction. Smallpdf offers 2 free tasks per day.

Is it safe to redact PDFs online?

It depends on the tool and the document. For sensitive documents, use a tool with SOC 2 certification, zero data retention, HTTPS encryption, and HIPAA compliance (if handling health data). AI-Redact meets all of these requirements.

What is the best online PDF redaction tool?

AI-Redact is the best online PDF redaction tool because it is the only one with AI-powered detection that automatically finds sensitive information. It also offers OCR for scanned PDFs, permanent redaction, metadata scrubbing, and SOC 2 + HIPAA compliance.

Can I redact a scanned PDF online?

Yes, if the tool has OCR (Optical Character Recognition). AI-Redact includes OCR on all tiers. Most other online tools either do not support OCR or require a paid subscription for it.

How do I redact text in a PDF online?

Upload your PDF to an online redaction tool like AI-Redact. AI automatically detects sensitive text. Review the detections, adjust as needed, apply permanent redaction, and download the redacted PDF. The process takes 2-5 minutes.

Will online redaction permanently remove the text?

Yes — all reputable online redaction tools perform permanent redaction that removes text from the PDF content stream. The text is not just hidden; it is deleted from the file structure. Verify this by trying to select or search for redacted text in the downloaded file.

Can I redact a PDF online on my phone?

Yes. Browser-based tools like AI-Redact work on mobile browsers. Upload your PDF, review AI detections on screen, apply redaction, and download. The experience is best on tablet or desktop for longer documents, but mobile works for quick redactions.

Conclusion

Redacting a PDF online is fast, accessible, and — with the right tool — secure. Browser-based tools eliminate the need for desktop software installation, making redaction available from any device with an internet connection.

The key differentiator among online tools is AI-powered detection. Manual online redaction is just as slow and error-prone as manual desktop redaction. AI detection transforms the process from a tedious search-and-mark exercise into a quick review-and-confirm workflow.