Originally published at ffmpeg-micro.com You need a thumbnail from a video file. Maybe you're building a video gallery, generating preview images for a CMS, or creating social media cards from uploaded content. The usual advice is to install FFmpeg on your server and write extraction scripts. That works until you need it in production. How FFmpeg Thumbnail Extraction Works FFmpeg can extract a single frame from any video using two flags: -ss to seek to a timestamp and -frames:v 1 to grab exactly one frame. ffmpeg -ss 5 -i input.mp4 -frames :v 1 thumbnail.jpg Enter fullscreen mode Exit fullscreen mode This grabs the frame at the 5-second mark and saves it as JPEG. The output format is determined by the file extension. Use .png for PNG, .webp for WebP. One detail that trips people up: the position of -ss matters. Placing it before -i uses input seeking, which is fast but jumps to the nearest keyframe. Placing it after -i decodes everything up to that point, which is slower but frame-accurate.…