Thum.io

Overview Thum.io is a website screenshot API that captures real-time desktop and mobile screenshots of websites. It streams the initial render as an animated GIF so users see content faster than traditional screenshot services. Developers and businesses use the API to integrate website snapshots into their own applications for previews, archiving, SEO reporting, and security purposes. Unlike alternatives that take 10–20 seconds to process a single request, Thum.io responds immediately with a loading spinner and then streams constant updates of the website's real-time render. Key Benefits Streams the initial render as an animated GIF so users get content immediately instead of waiting 10–20 seconds. Because the screenshot is streamed live, Thum.io can wait extra seconds to capture the full load of every website including late-loading JavaScript and video banners. Offers both referer-based authentication and signed requests with custom expiry times for different security requirements. Self-serve admin panel lets users create and destroy as many API keys as needed at any time. First 1,000 website screenshot impressions per month are completely free without requiring a signup. How It Works You place an img tag pointing to the Thum.io URL with the target website appended, like <img src="//image.thum.io/get/http://www.google.com/" /> . Thum.io immediately returns the first frames of a loading spinner, then streams constant GIF updates of the page as it renders in a 1200x1200 pixel browser. For advanced use you add query parameters for viewport width and crop height, for example <img src="//image.thum.io/get/width/100/crop/600/http://www.google.com/" /> . Use Cases Web developers building a website builder — use Thum.io screenshots to show customers a live preview of their work. SEO agencies — capture screenshot proof of linkbacks and rankings to share with clients. Security appliance vendors — block dangerous emails or websites while letting end users view the content as a safe image via Thum.io. DevOps teams — automate full-page screen captures as part of CI/CD or archiving workflows. Design testers — use the mobile emulation and responsive design features to test sites on different device widths. Content archivists — take periodic snapshots of websites over time to create timelapse-style archives. Why Choose This Product Thum.io suits developers and teams who need fast, reliable website screenshots at scale without managing their own rendering infrastructure. The streaming approach is its main differentiator — users see content in under a second instead of waiting for a full capture cycle. Limitations include a monthly minimum on paid plans and the free tier being capped at 1,000 impressions per month without access to advanced features like unbranded loaders or adjustable viewport width.