Gmail signature image not showing? Every cause, every fix

The 6 causes

Diagnose it in 60 seconds

1. Open the image URL in an incognito window — if it doesn't load there, it won't load in mail (causes 1-4).
2. Confirm the URL starts with https://.
3. Send a test to a different account (not your own) and check it.
4. If it shows for you but not others → Drive permissions (cause 2) or hotlink blocking (cause 4).
5. If you recently replaced the image → rename the file (cause 6).

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Diagnosing it in order

Work through these in sequence — the first two account for most cases.

1. Open the image URL in a private browsing window. If it does not load there, it will not load for recipients either. This single test resolves most reports.
2. Check it is HTTPS. An http:// image on an HTTPS-delivered email is commonly blocked as mixed content.
3. Check permissions. Files in Google Drive, Dropbox or a private bucket usually require a login — the sender is authenticated and sees it, the recipient is not and does not. This is the classic false-negative.
4. Check for hotlink protection. Some hosts block requests that do not originate from their own domain, which is exactly what an email client does.
5. Confirm the image was not embedded from your local disk. Dragged-in files can travel as attachments rather than rendering inline.
6. Ask the recipient whether images are blocked. Many clients block remote images by default until the reader allows them — this is not a fault, and it is why the signature must read correctly with images off.

Why it looks fine to you and broken to them

The most confusing version of this problem is when the sender genuinely cannot reproduce it. There are three common reasons, and all are about context rather than the file. You may be authenticated to the host — a Drive or intranet image loads for you and nobody else. Your client may have cached the image from an earlier send, so it appears even after the source moves or breaks. And Gmail serves remote images through its own proxy, which caches aggressively; a replaced image can therefore keep showing the old version for some recipients and nothing for others. The reliable test is always a fresh private window on a device that has never seen the signature.

Preventing it permanently

Three habits eliminate almost all of these. Host signature images on a public HTTPS URL with no authentication — a proper web host or CDN, not a file-sharing service. Give every image explicit width and height attributes so the layout holds while it loads and Outlook cannot resize it, at the dimensions in the sizing guide. And design so the signature is complete without images — text as real text, never inside a picture. A generator that outputs email-safe HTML and hosts your images handles all three by default; if the signature is missing entirely rather than just the images, see signature not showing.

Written and maintained by the ProSignature team. Competitor pricing and feature claims on this site are verified against each vendor's live page on the day of writing — last verified 26 July 2026. No affiliate links. How we work.

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