Screenshots often contain information that shouldn't be shared—email addresses, passwords, personal data, financial details, or confidential business information. Before sharing or publishing any screenshot, you need to properly obscure this sensitive content.
But not all blurring is created equal. Here's how to do it right.
Why Proper Redaction Matters
A poorly redacted screenshot can expose sensitive information:
- Some blur effects can be reversed with the right tools
- Thin redaction bars may leave text readable around the edges
- Inconsistent redaction can miss some instances of sensitive data
- Metadata in screenshots can reveal information too
The goal isn't just to make information hard to read—it's to make it impossible to recover.
Methods for Obscuring Information
Pixelation (Mosaic)
Pixelation replaces an area with large, blocky pixels that hide the underlying content.
Pros:
- Generally secure when applied correctly
- Clearly indicates intentional redaction
- Looks "official" for documentation
Cons:
- Can sometimes be partially reversed if blocks are too small
- Doesn't look as clean as other methods
Best practice: Use large pixel blocks (8x8 or larger) and apply to an area larger than just the text.
Solid Color Blocks
Cover sensitive information with a solid rectangle.
Pros:
- Completely secure—nothing to reverse
- Clean, professional appearance
- Works on any background
Cons:
- Obvious that something was removed
- Can be jarring in certain contexts
Best practice: Match the color to your annotation scheme, or use black/white for a neutral look.
Gaussian Blur
The traditional blur effect that creates a soft, out-of-focus look.
Pros:
- Looks natural
- Less jarring than solid blocks
Cons:
- Can potentially be reversed with enough effort
- May not fully obscure high-contrast text
- Security depends on blur intensity
Best practice: If using Gaussian blur, apply it heavily and to an area larger than the text. For truly sensitive data, use pixelation or solid blocks instead.
What to Blur
Before sharing any screenshot, check for:
Personal Identifiers
- Full names (when privacy matters)
- Email addresses
- Phone numbers
- Home addresses
- Profile photos
Authentication Data
- Passwords (should never be visible anyway)
- API keys and tokens
- Session IDs
- Two-factor codes
Financial Information
- Credit card numbers
- Bank account details
- Transaction amounts (if sensitive)
- Billing addresses
Business Sensitive Data
- Client names (unless permitted)
- Proprietary information
- Internal URLs or endpoints
- Employee information
Browser and System Data
- Browser bookmarks and history (can reveal private browsing)
- File paths (can reveal username or system structure)
- Network information
Common Mistakes to Avoid
Blur Is Too Light
A light blur over text is often reversible or simply readable. When in doubt, blur more heavily or use solid redaction.
Inconsistent Application
You blur an email address in one place but leave it visible in another (perhaps in a tab title, URL bar, or notification). Check the entire screenshot systematically.
Leaving Metadata
Screenshots can contain metadata including location, device information, and more. Strip metadata before sharing using your image editor's export options or a dedicated tool.
Using the Wrong Tool
The highlighter or opacity brush in some tools doesn't fully obscure text—it just colors it. Ensure your tool actually removes information, not just colors it.
Missing Reflections and Previews
Watch for thumbnail previews, browser suggestions, and other places where information might appear twice in a screenshot.
A Systematic Approach
Before sharing any screenshot:
- Scan for personal information — Names, emails, phone numbers
- Check authentication data — Passwords, keys, tokens
- Review URLs and file paths — These often contain usernames or internal information
- Look at the edges — Notifications, tabs, bookmarks, system tray
- Consider context — What could someone infer even from blurred information?
- Apply redaction — Use pixelation or solid blocks for maximum security
- Review the result — Look at the final image as if you've never seen it before
Tools That Make It Easy
Dedicated screenshot tools like Snapp include blur and redaction features designed for this purpose. They're faster than general image editors and less likely to leave information exposed.
Look for:
- One-click blur/pixelation
- Adjustable intensity
- Easy selection of areas to obscure
- Preview before export
When in Doubt, Leave It Out
If you're unsure whether something should be blurred, blur it. The minor inconvenience of over-redaction is nothing compared to the potential consequences of exposing sensitive information.
Privacy and security aren't just nice-to-haves—they're essential. A few extra seconds of careful redaction can prevent serious problems down the road.