How to Blur Sensitive Info in a Screenshot (So It Can't Be Recovered)

Quick answer: cover the whole field with a strong blur or an opaque box, make sure the edit is flattened into the image rather than sitting on top as a removable layer, and save it as a new file. In Chrome, Screshot does this in four steps: capture, pick Blur, drag over the data, then copy or download. Avoid light pixelation. Public tools can reverse it.

Screenshots are the fastest way to show a bug, explain a step or escalate a ticket. They also travel further than you expect: from Slack to Jira, from Jira to a vendor, from a vendor into a slide deck. A single unblurred email address or card number in that chain is a privacy incident. This guide shows what to hide, which hiding methods actually work, and how to do it in seconds.

What counts as sensitive info in a screenshot

Blur anything that identifies a person or unlocks an account:

Personal data: names next to account details, email addresses, phone numbers, home addresses, dates of birth.
Payment data: card numbers, IBANs, bank account numbers, invoice totals tied to a named customer.
Credentials: passwords, API keys, access tokens, session IDs, one-time codes, QR codes.
Internal identifiers: customer IDs, order numbers, ticket links, internal URLs and hostnames.
Health, HR and legal data: anything covered by HIPAA, GDPR special categories or an NDA.
Other people's content: chat messages, notifications and avatars from colleagues who never agreed to be in your screenshot.

If you are unsure, blur it. A blurred field never caused an incident.

Blur vs pixelate vs black box: which is actually safe?

Not every way of "hiding" text hides it.

Three ways to hide a card number: pixelation can be reversed, a light blur can be guessed, a strong blur or solid box over the whole field is safe

Pixelation (mosaic) is the weakest. In 2020 the open-source tool Depix showed that passwords pixelated with a standard box filter can be reconstructed. In 2022 Bishop Fox released Unredacter, which recovered text that had been pixelated in ways people assumed were safe. Both work the same way: guess a character, pixelate the guess with the same settings, and keep the guess that produces matching blocks.
A light blur has the same problem. If the text is still roughly readable in shape, or the blur is small compared with the letters, the same guess-and-compare approach can work.
A strong blur over the whole field, or an opaque box, is safe. Cover the entire value, extend a little past its edges, and use enough strength that no letter shapes remain. For passwords, keys and full card numbers, an opaque box is the most conservative choice.

Three rules that apply whatever tool you use:

1. Cover the whole field, not just the middle. A visible first or last character narrows the guess dramatically.

2. Hide the length too. Make the blurred area the same width for every value, so "Jo" and "Jonathan" look identical.

3. Never rely on the reader's goodwill. If you would not post the original publicly, blur it as if you were.

How to blur part of a screenshot in Chrome with Screshot

Screshot is a free Chrome extension that captures, blurs and annotates screenshots on your device. Nothing is uploaded when you capture, blur, copy or download.

Four steps: capture with Ctrl+Shift+S, choose the Blur tool, drag over the sensitive area, then copy or download the PNG

1. Capture. Press Ctrl+Shift+S (or click the Screshot icon) to capture the visible area of the page.

2. Choose Blur. In the editor toolbar, select the Blur tool.

3. Drag over each sensitive field. Cover the whole value plus a small margin. Repeat for every email, number or name you need to hide. Use Crop to remove anything you do not need at all.

4. Copy or download. Click Copy to paste the image straight into Slack, Jira, Gmail or a support ticket, or Download to save a PNG.

The blur is written into the image pixels, not laid on top as a separate layer, so the person you send it to receives only the blurred version.

Add Screshot to Chrome — free

The overlay trap: when a black box is not enough

Where you draw the box matters as much as how you draw it.

Left: a black box drawn as a separate layer can be moved or deleted to reveal the text. Right: a flattened image has only one layer, so there is nothing to remove

Shapes in documents and slides stay editable. A black rectangle drawn in a PDF editor, a word processor or a slide tool is usually a separate object. Anyone who opens the file can move it, delete it or copy the text underneath.
Cropping is not always deletion either. In 2023 the aCropalypse bugs (CVE-2023-21036 in Google Pixel's Markup and CVE-2023-28303 in Windows Snipping Tool and Snip & Sketch) meant that some cropped PNGs still contained data from the original, uncropped image. Both have since been patched, but they show why the safest file is a newly exported one.

The fix is the same in every case: flatten the image and export a new file. Copy the edited image to the clipboard or save it as a new PNG instead of overwriting the original.

6 places sensitive data hides in a screenshot

The obvious field is rarely the only one. Check these before you send.

A browser screenshot with six places sensitive data hides: tab title, address bar, a notification, the signed-in account, a sidebar list and the bottom of the page

1. Tab titles. Inbox counts, customer names and document titles appear in tabs.

2. The address bar. URLs often contain customer IDs, emails, search terms or tokens.

3. Notifications. A chat or email preview can pop up at the exact moment you capture.

4. The signed-in account. Your own name, email and avatar in the corner of the app.

5. Side panels and lists. Recent conversations, contact lists and search history.

6. Below the fold in full-page captures. A full-page capture includes everything you did not scroll to.

Capturing only the area you need is the simplest defence. If it is not in the image, it cannot leak.

Checklist before you send a screenshot

Every email, phone number, card number and name is fully covered
Blur is strong enough that no letter shapes are visible
Tab titles, URLs, notifications and account details are cropped or blurred
The image is flattened (no separate shapes or layers)
You are sending a newly exported file, not an overwritten original
The person receiving it actually needs every part that is still visible

FAQ

Can a blurred screenshot be unblurred?

A strong blur that covers the whole field cannot be meaningfully reversed. Pixelation and light blurs are different: tools like Depix and Unredacter have recovered text from them by guessing and comparing. If the information is critical, use a strong blur or an opaque box.

Is pixelating text safe?

Not reliably. Pixelation is the method that public research has reversed most often. Use a strong blur or a solid box instead.

Does Screshot upload my screenshot to blur it?

No. Capturing, blurring, copying and downloading all happen on your device, and nothing is uploaded. Cloud sharing is in development and will be opt-in: only the image you choose to share, after your edits, would be uploaded.

Can I blur a screenshot without installing anything?

Yes, but check how your tool saves the result. Draw an opaque filled shape over the data, then export or save a new flattened image file. Avoid tools that keep the shape as a separate, removable object.

What is the fastest way to blur screenshots for a support or QA team?

Use a tool where blur is one click away from capture, so blurring is never the step people skip. With Screshot, IT can force-install the extension for everyone from the Google Admin console, Microsoft Intune or Group Policy. See the deployment guide.