# How to add a QR code to an email signature

> Insert the code as a hosted image URL — the UseQR API link works directly in Gmail, Outlook and Apple Mail signature editors — displayed at roughly 100–120 px, about 2.5–3 cm on screen. Test in dark mode before rolling it out: several clients invert or recolour images, and an inverted QR code stops scanning.

Source: https://useqr.app/docs/how-to/how-to-add-a-qr-code-to-an-email-signature · Last reviewed 2026-08-21 · UseQR is free forever, MIT licensed, no signup.

---

## Should it be there at all?

Quick honesty check first: the recipient is already on a device where **links are
clickable** — a QR code in an email mostly serves the printed email, the projected email,
or the phone-scans-desktop-screen handoff. The cases where it earns its pixels (and the
ones where it does not) are covered on the
[email signatures surface page](/qr-codes-on/email-signatures). If you are here, you have
a case; on to the how.

## 1. Choose the payload

- **vCard** — recipient scans, your contact card opens ready to save. The
  strongest signature use, since it does something a link does not do well.
- **URL** — booking page, portfolio, LinkedIn. Keep it short; signature codes are
  small, and longer payloads mean denser codes.

## 2. Use a hosted image URL, not an attachment

Signature editors accept images two ways, and the difference matters:

- **Hosted URL (right)**: the signature references an image by URL. The
  [keyless API link](/docs/developers/free-qr-code-api-no-key) is itself a stable hosted
  image — paste it wherever the editor asks for an image address:

```
https://useqr.app/api/v1/qr?data=https://example.com/book&size=240
```

- **Embedded/attached image (avoid)**: some editors inline the file, which triggers
  attachment icons on every mail you send and gets stripped by some corporate gateways.

In **Gmail**: Settings → See all settings → Signature → insert image → Web Address (URL).
In **Outlook** and **Apple Mail**: paste or drag the image into the signature editor —
these embed it; acceptable, just test a sent mail. Company-wide rollouts through
signature-management tools take the URL form natively.

## 3. Size: small, but not too small

Signature codes render around **100–120 px**, which is roughly 2.5–3 cm on a typical
display — comfortably scannable by a phone
pointed at the screen, and printable at
just about the 2 cm floor if the email is printed at 100%. Below ~80 px rendered, dense
vCards start failing — trim the vCard to name, one number, one email, one URL rather than
shrinking further.

## 4. The dark-mode trap

The single biggest signature-specific failure: **dark-mode email clients transform
images**. Outlook's dark mode inverts light images — turning your code into
[a light-on-dark inversion that scanners reject](/docs/troubleshooting/qr-code-inverted-and-unreadable) —
and other clients dim them. Defences:

- Use a code with a **solid white background** (never a
  transparent one, which inherits the
  dark client background directly).
- Send test mail to accounts in Outlook dark mode, Gmail dark mode and Apple Mail dark
  mode before rolling anything out to a team. The general logic is the same as
  [QR codes on dark-mode websites](/docs/design/qr-code-in-a-dark-mode-website).

## 5. Test the round trip

Send yourself the email, then: scan the code off the received message on another phone,
check it in dark mode, forward it once (forwarding sometimes recompresses), and print it.
Paste the image URL into the [validator](/validate) to confirm the payload is exactly
right — a signature ships thousands of times, so a typo ships thousands of times too.

## Gotchas

- **Remote-image blocking**: Outlook and some corporate setups hide remote images until
  the reader clicks "download pictures" — one more reason the code should supplement,
  not replace, the plain-text details in your signature.
- **Reply chains** shrink and sometimes strip signatures; expect the code to be scanned
  from first-contact emails, not thread number nine.
- **Keep alt text** ("Scan to save my contact details") so blocked-image and screen-reader
  cases still convey what the block is — see
  [alt text guidance](/docs/design/qr-code-alt-text-and-screen-readers).

Generate the signature code: [a vCard code](/vcard) for contact saving, or a
[URL code](/url?data=https://example.com) for bookings.

## FAQ

### How do I put a QR code in my Gmail signature?
Settings → See all settings → Signature, insert image, choose Web Address (URL), and paste a hosted QR image URL such as a UseQR API link. Size it around 100–120 px.

### What should an email signature QR code link to?
A vCard is the strongest choice — scanning saves your contact details straight to the phone. Otherwise a short booking or portfolio URL. Avoid anything with a long tracking-parameter tail.

### Why does my signature QR code fail in dark mode?
Some clients, notably Outlook, invert or dim images in dark mode, producing a light-on-dark code most scanners reject. Use a solid white background and test in dark-mode clients before rollout.

### Is a QR code in an email signature even useful?
Only for print, projection and cross-device moments — recipients on the same device can just click a link. It earns its place when you want screen-to-phone handoff, such as saving a contact.

## Try it

- https://useqr.app/url
- https://useqr.app/vcard
- https://useqr.app/validate