Which resolution presets are available?

Choose 1080p (1920×1080), 720p (1280×720), 480p (854×480), or 360p (640×360). You can also pick Custom and enter exact width and height values in pixels.

Will resizing change the aspect ratio?

Not when "Keep aspect ratio" is checked — the height is computed automatically from the width so the picture is never stretched. Uncheck the option only if you intentionally want to squash or stretch the frame.

Can I upscale a video to a higher resolution?

Technically yes — entering a larger width than the source will upscale it — but ffmpeg.wasm does not include AI super-resolution, so the result will look soft. Resizing down to a smaller resolution always preserves quality better than upscaling.

Does resizing reduce file size?

Yes, dramatically. Halving the resolution removes 75% of the pixels per frame, so a 1080p → 720p resize typically produces a file roughly 50% smaller at comparable quality.

Is the audio re-encoded too?

No. Audio is stream-copied with no re-encoding, so audio quality is identical to the source and adds essentially no extra processing time.

Is my video uploaded anywhere?

No. ffmpeg.wasm runs entirely inside your browser. The file is processed locally and never leaves your device.

Resize Video Online — 1080p, 720p, 480p in Browser

Video Resizer

Resize any video to 1080p, 720p, 480p, 360p or a custom resolution — entirely in your browser, no upload.

100% client-side · no upload

Video file (MP4, WebM, MOV…)

Load a video file to begin.

How to resize a video

Select your video file — MP4, WebM, MOV all work.
Pick a preset (1080p, 720p, 480p, 360p) or choose Custom for exact pixel dimensions.
Keep "Keep aspect ratio" checked unless you specifically need to stretch the frame.
Click Resize video and download the result.

Common use cases

Email attachments: Shrink a 4K phone clip down to 720p so it fits inside a 25 MB mail attachment limit.
Web upload limits: Resize to 480p before uploading to a forum or chat that caps video resolution.
Storage savings: Reduce a backup library of HD recordings to 720p for long-term archival.
Mobile playback: Generate a smaller 480p version optimised for slower mobile data connections.

Related tools: Video Compressor · Video Cropper · Change Aspect Ratio · Video to MP4

常见问题

Which resolution presets are available?: Choose 1080p (1920×1080), 720p (1280×720), 480p (854×480), or 360p (640×360). You can also pick Custom and enter exact width and height values in pixels.
Will resizing change the aspect ratio?: Not when "Keep aspect ratio" is checked — the height is computed automatically from the width so the picture is never stretched. Uncheck the option only if you intentionally want to squash or stretch the frame.
Can I upscale a video to a higher resolution?: Technically yes — entering a larger width than the source will upscale it — but ffmpeg.wasm does not include AI super-resolution, so the result will look soft. Resizing down to a smaller resolution always preserves quality better than upscaling.
Does resizing reduce file size?: Yes, dramatically. Halving the resolution removes 75% of the pixels per frame, so a 1080p → 720p resize typically produces a file roughly 50% smaller at comparable quality.
Is the audio re-encoded too?: No. Audio is stream-copied with no re-encoding, so audio quality is identical to the source and adds essentially no extra processing time.
Is my video uploaded anywhere?: No. ffmpeg.wasm runs entirely inside your browser. The file is processed locally and never leaves your device.