Email client support

How UrgencyKit countdown timers render across email clients.

Every UrgencyKit timer is delivered as a plain image, so it displays in essentially every email client — no scripts, no custom HTML. This page is the honest detail on how the static (JPEG) and animated (GIF, with the Seconds segment) timers behave.

Compatibility

Client	Static timer (JPEG)	Animated timer (GIF)
Gmail (web & mobile apps)	Fully supported	Animates
Apple Mail (macOS & iOS)	Fully supported	Animates
Outlook on the web / Microsoft 365	Fully supported	Animates
Outlook desktop (Windows)	Fully supported	First frame only (static)
Yahoo Mail	Fully supported	Animates
Other clients	Fully supported	Animates or first frame

Good to know

Outlook desktop for Windows uses the Word rendering engine and shows only the first frame of an animated GIF — your countdown appears frozen at its starting value there. Every image-based countdown tool shares this limitation. If your audience is Outlook-desktop-heavy, the static (JPEG) timer is the safest choice; it renders identically everywhere.
Most clients block external images until the recipient chooses to display them — universal to any live email image. Once images load, the countdown reflects the current time on each open.
We render timers as JPEG, not WebP or PNG: WebP fails in Outlook and Gmail, while JPEG is email-safe and compact.

Need a per-recipient deadline? The embed panel can format the ?end= value for your email platform's merge tag, so each subscriber sees their own countdown.