The export is a bundle of choices.
Media exports combine dimensions, frame or sample rate, codec, bitrate and duration. File size is the result of those choices, not one magic quality switch.
Smart / Local Tools
Pick the best thumbnail from a video.
Sample frames across your clip, surface clean candidates, and choose the frame that communicates the video best.
Best thumbnail ≠ highest score: OutMonkey ranks focus and exposure. You should still choose the frame with the clearest face, action, product or story.
Private by design: frame extraction and scoring happen in your browser.
Useful to know
Four things worth knowing.
Exporting is not mastering.
A browser utility is good for a focused conversion or edit, but it is not colour grading, audio mastering, motion tracking or a full timeline.
Play the whole thing.
Automatic results still need a human check around edges, text, faces and small details.
Match the destination.
Play the export all the way through once. Broken audio, a bad final frame or a mistimed subtitle often hides near the end.