# QR codes on email signatures

> A QR code in an email signature is scanned from a second device — someone photographing their own screen — so size it in pixels: 80–120 px displayed, exported at 2× for retina. Most email clients block images by default, so a text link is still required.

Source: https://useqr.app/qr-codes-on/email-signatures · Last reviewed 2026-08-21 · UseQR is free forever, MIT licensed, no signup.

---

| Typical scan distance | **screen** |
|---|---|
| Minimum code width | **80–120 px** |
| Error correction | **M** |

## Images are blocked by default

Outlook, Gmail and most corporate clients block remote images until the reader clicks
*show images*. A signature that depends on a QR code is a signature that usually shows a
broken-image box. Always include the plain text link.

## Sizing for screens

Display at **80–120 px**. Export at **2×** (160–240 px) and set the display size in HTML,
so the code stays crisp on high-DPI displays.

```html
<img src="…" width="100" height="100" alt="Scan for my contact details">
```

## Embed, do not hotlink

Base64-embed the image (`data:` URI) or attach it inline (`cid:`). Hotlinking to an image
on your site means every open leaks a signal to your server and breaks entirely if the file
moves. Some clients strip `data:` URIs, so `cid:` inline attachment is the most reliable.

## Alt text

A QR code is invisible to a screen reader. `alt="Scan for my contact details"` is the
minimum; the text link beside it is what actually serves those readers.

## Keep it modest

A signature block with a 200 px QR code, a logo and three social icons is why people mute
threads. One small code, one line of text.

## Try it

- https://useqr.app/url
- https://useqr.app/size-calculator
- https://useqr.app/validate