Content creators need to know how their thumbnail and title will look before publishing. This free tool runs in your browser: upload your thumbnail image and type the video title. You get a live preview that mimics YouTube on desktop (homepage style), mobile, and dark mode. No file is sent to any server; everything is done locally with FileReader and CSS.

Use the view toggles to switch between desktop, mobile, and dark mode. The preview uses the same aspect ratio (16:9) and title placement as YouTube so you can adjust your design before going live. Great for technical and non-technical creators who want their links to stand out in search and recommendations.

A thumbnail that looks good on all devices and themes can improve click-through rates. This previewer is free, requires no sign-up, and keeps your images private. Use it for every video before you hit publish.