Developer Hub

Build with Castimer

Add countdown timers to your website, control them via API, and trigger automations with webhooks. Free to start.

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FREE

Embed Widget

Drop a countdown timer onto any website with a single iframe. No backend required. Works with any platform.

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PRO

REST API

Create and control timers programmatically. Integrate with your app, dashboard, or automation tools.

View API Docs

PRO

Webhooks

Get notified when a timer starts, pauses, or hits zero. Connect to Slack, Zapier, or your own backend.

Webhook Guide

Up and running in minutes

Choose your integration method and copy the code to get started.

Embed a Timer

Copy this iframe code and paste it into your HTML. The timer will display inline on your page.

<iframe
  src="https://castimer.com/widget?type=countdown&duration=300&theme=light"
  style="width:100%;max-width:360px;height:360px;border:none;"
  title="5 Minute Countdown Timer"
></iframe>

What developers build with Castimer

See how developers and teams use Castimer to add timers to their products.

Website countdown widgets for product launches

Event registration page timers

Gym and classroom screen displays

Automated meeting room timer boards

Slack bots that start timers via command

Zapier automations triggered when time is up

Start building for free

Free plan includes embed widgets and public event API. No credit card required.

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