Email countdown timers: how they work and how to use them well

A countdown in an email is an image that gets generated the moment someone opens the message. This guide covers what happens between pasting the timer and the reader seeing it, which type to use, where to put it, how each email client handles it and when you're better off without one. If you just want the timer, the generator below makes one for free, no signup.

In this guide

• What an email countdown timer is
• How it works under the hood
• Fixed, evergreen or recurring
• Where to place it
• Compatible email platforms
• Outlook, Gmail and Apple Mail
• Privacy
• Accessibility
• When not to use one

What is an email countdown timer?

It's an animated GIF showing the days, hours, minutes and seconds left until a date. In the email code it's a regular <img> tag pointing to a URL on our server, such as https://kauntodaun.com/t/k3x9q2m7ab.gif. What changes is the image that URL returns: it depends on when it's requested.

That's why two people who open the same email a day apart see different times, and both are right.

How does it work under the hood?

1. You create the timer. You pick the date, time zone, style and colors. It's saved under an ID and you get the code to paste.
2. You paste it into the email. In an HTML block or, if your platform only accepts images by link, as an image with the URL.
3. Someone opens the email. Their email client requests the image. Our server works out the time left at that instant and returns a fresh GIF.
4. The GIF animates. It holds 30 one-second frames and loops. If it stops because it hits zero, it stays on the final frame.

The response carries headers asking clients not to cache the image, so each open gets the current time. If a reader leaves the email open for more than 30 seconds, they'll see the seconds jump back; reopening it brings a new image.

When the deadline passes, the GIF shows the expired message you chose ("This offer has ended," for example) or a transparent 1-pixel image if you'd rather the space disappear. And if the date changes, you can edit the timer after sending: the change also reaches emails already sitting in inboxes.

Why not use JavaScript?

Because it doesn't run in email. Mailchimp's help center puts it this way: most email clients block JavaScript to protect against viruses, and Mailchimp strips it from the code you paste. A countdown that moves inside an email has to arrive already drawn, and the format that animates almost everywhere without code is the GIF.

How big is the GIF?

Small, because only part of each frame changes. The first frame is complete; the other 29 carry only the rectangle of digits that change, and every frame shares a single color palette (so nothing flickers).

On our server, on October 1, 2026, the default timer (blocks style, medium size) weighed between 17.5 and 19.8 KB depending on the font, and the free styles ranged from 13 to 32 KB. The heaviest Pro style, glass, came in around 47 KB. This site's previous generator served that same default timer at 374 KB.

If you only show days (the d unit), every frame is identical and the GIF collapses into one.

Fixed, evergreen or recurring: which should you pick?

An evergreen timer without a recipient starts over on every open. If the person opens the email tomorrow, they see 48 hours again. Don't use it for an offer with a concrete end: you'd be telling the reader something that isn't true (more on that below).

A per-recipient evergreen needs your platform to add a tag with each contact's ID to the URL (?rid=). That person's first open sets the start, and later opens show what they have left. Each platform guide lists the tag to use.

Where should it go in the email?

We don't know of any published study comparing countdown placements in email, so this is practical judgment:

• Next to what expires. The timer explains a deadline, so put it beside the offer and the button that claims it. Far from the button, readers have to hunt for it.
• With the date written out. "Ends Sunday, Dec. 6 at 11:59 p.m. ET" in text. It still reads when images are blocked or the GIF doesn't animate.
• No wider than the template. If your email is 600 px wide, keep the timer at 600 or less so it doesn't get cropped on phones.
• On the same background as the section. If the timer's color doesn't match the block, you'll see a frame around it. The transparent option works when the background is a flat color.
• One per email. Two countdowns ticking toward different moments read as a contradiction.

If the deadline is weeks away, seconds add nothing. Drop them and keep days and hours.

Does it work with my email platform?

Yes, if your platform accepts an HTML code block or an image by URL, which almost all do. The generator gives you the code in three formats: HTML (a table holding the image, with & already escaped), a plain URL and a version set up for Klaviyo.

We have step-by-step guides covering which block to use, the tag for per-recipient timers and how to test:

• Klaviyo
• Mailchimp
• HubSpot
• Shopify Email
• Brevo
• Mailjet
• ActiveCampaign

For campaigns with a known date there are ready-made countdowns, like the ones for Black Friday and Cyber Monday.

How does it look in Outlook, Gmail and Apple Mail?

Your ESP delivers the email; whether the GIF animates is up to the reader's email client.

Outlook for Windows. According to Microsoft, Outlook for Microsoft 365, 2021 and 2024 play animated GIFs by default. If the user has Windows animations turned off, they see only the first frame. Klaviyo adds that Outlook 2007, 2010 and 2013 always stay on that first frame. On top of that, classic Outlook blocks automatic picture downloads from the internet out of the box: until the reader clicks "Download Pictures," the timer doesn't show. Our guide to countdown timers in Outlook goes into detail.

Other versions of Outlook. Outlook for Mac also doesn't download internet pictures by default. We haven't found Microsoft documentation on how the new Outlook for Windows, Outlook on the web or Outlook for Mac handle animated GIFs. If your list uses them, test them.

Gmail. Google checks images before displaying them, and senders can't use image loading to find out where the reader is. A countdown that tries to guess the time zone from the IP address isn't reliable in Gmail; ours uses the zone you choose, the same for everyone.

Apple Mail. With Mail Privacy Protection on, Apple downloads remote content in the background through two relays, whether or not the email is opened. Klaviyo warns that countdowns may not render correctly in Apple Mail because of that preloading. With a per-recipient timer, the window may start when the email arrives rather than when it's read.

In every case, the worst outcome with our GIF is a still image showing the time left at open, because the first frame is complete: digits, labels and background. That's why we keep saying to write the date in the copy too.

What data does the engine store?

The minimum needed to count impressions and run per-recipient evergreen timers:

• Each open. We log the time, the timer and, if the URL carries a rid, a hash of that ID. The impression log doesn't include the reader's IP address or email. Opens are added up every hour and the file is deleted.
• The rid. It's stored as a salted hash (truncated SHA-256), never in plain text. For a per-recipient evergreen timer, that hash is kept alongside the time of the first open.
• Unreplaced tags. If the URL arrives with the ESP tag as is (this happens in previews), the engine ignores it.

Even though the engine hashes what it receives, it's better not to put the reader's email address in the image URL: it would travel in plain text and end up in the logs of any server along the way. Use the internal contact ID your platform provides.

Each timer's stats are kept for 30 days on the free plan with an account and 12 months on paid plans.

How do you make it accessible?

Alt text with the date. WCAG 2.2 asks for every informative image to have an equivalent text alternative. The code you copy comes with alt="Countdown timer"; change it to the deadline, for example alt="Offer ends December 6 at 11:59 p.m. Eastern". Alt text doesn't update, so it should say when the offer ends, not how long is left.

The date in the body as well. A screen reader user, someone with images blocked and someone with animations off all get the same information.

Contrast. WCAG asks for a minimum contrast of 4.5:1 for text inside images (3:1 if it's large). The digits usually pass; check the labels (DAYS, HOURS), which are small and use the secondary color.

Motion. WCAG criterion 2.2.2 asks that content moving on its own for more than five seconds can be paused. A GIF inside an email has no such control. What does happen in Outlook for Windows is that it follows the system's animation setting: people who turn animations off see the first frame. Our GIF changes once per second and doesn't flash.

When shouldn't you use a countdown?

When there's no real deadline. A countdown that hits zero while the offer carries on, or that resets, is what the FTC calls a "baseless countdown timer" in its 2022 report on dark patterns. In the EU, the Unfair Commercial Practices Directive lists falsely stating that a product is available only for a very limited time, to push an immediate decision, among the practices that are unfair in all circumstances. Our guide to urgency in email marketing covers this in more depth.

When you plan to extend the offer quietly. If you extend it, say so in the next email. Editing the timer changes the date in every sent email, and the copy in the older ones will still mention the old date.

In emails without a date. A newsletter or a new-content announcement has nothing that expires. A timer there only makes the next one you use less believable.

When the end is months away. A written date is easier to grasp than seconds ticking for 90 days.

Before you schedule any send with a countdown, send yourself a test at a Gmail address and an Outlook address.