How do I resize a video online?

Upload your video, choose a resolution (and optional aspect ratio), click Resize video, then download the MP4.

Is this video resizer free?

Yes. You can resize video online free in your browser.

Are my videos uploaded to a server?

No. Resizing runs locally with FFmpeg WebAssembly, so files stay on your device.

How do I change video resolution?

Pick 1080p, 720p, 480p, or 360p. The tool scales the video to that height (keeping aspect unless you pick another ratio).

How do I change video aspect ratio?

Select 16:9, 9:16, or 1:1, then Pad (letterbox) or Crop (fill). That acts as a video aspect ratio changer / stretcher alternative without distorting when you use pad or crop.

Can I resize MP4 for Instagram or TikTok?

Yes. Use 9:16 for vertical Stories/Reels/TikTok-style clips, or 1:1 for square posts, then download the resized MP4.

Is resize the same as compressing / reducing file size?

Not exactly. Resize changes dimensions (and optional aspect). Lower resolution often reduces file size too, but for CRF-focused shrinking use Compress Video.

Will quality drop when I resize?

Downscaling always changes pixels. Keep CRF lower (e.g. 20–23) for sharper results; raising CRF makes a smaller file with more compression.

What formats are supported?

MP4, MOV, and WebM input; output is always a web-ready MP4 (H.264 + AAC), up to 200 MB.

Drop video here or

Output is MP4 (H.264 + AAC). First run downloads FFmpeg (~25 MB) once in this browser.

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Resize video online — video resizer

Resize video online free. Change video resolution or aspect ratio (16:9, 9:16, 1:1) for Instagram and TikTok — MP4 output, no server upload.

What is a video resizer?

A video resizer (video resolution changer) changes the pixel dimensions of a clip — for example resize MP4 to 720p or 1080p, or change video aspect ratio to 9:16 / 1:1 for Instagram and TikTok. This free resize video online tool runs in your browser with FFmpeg WebAssembly, so files stay on your device. For shrinking file size without targeting resolution, use the compress video tool.

Video resizer features

Resize videos and change resolution online, privately in the browser.

Resize video online
Upload MP4, MOV, or WebM and download a resized MP4 at 1080p, 720p, 480p, or 360p.
Video resolution changer
Lower or set resolution when platforms, editors, or uploads need a specific height.
Video aspect ratio changer
Switch to 16:9, 9:16, or 1:1 with pad (letterbox) or crop (fill).
Resize MP4 for social
Prepare clips for Instagram Stories / Reels or TikTok-style vertical frames.
No server upload
Resizing runs locally with FFmpeg WebAssembly.
Quality control (CRF)
Tune H.264 quality so you can resize without unnecessary detail loss.

How to resize a video online

Change the size of a video or resize MP4 in three steps.

Upload video
Drop an MP4, MOV, or WebM file (up to 200 MB).
Pick resolution and aspect
Choose 1080p–360p, optional 16:9 / 9:16 / 1:1, and pad or crop.
Resize and download
Click Resize video, then save the MP4.

Great for

Common video resize and resolution-changer scenarios.

Instagram and TikTok framing
Resize video for Instagram or TikTok with 9:16 / 1:1 aspect presets.
Resolution targets
Deliver 720p or 480p when a site or editor asks for a specific resolution.
Downscale before share
Change video resolution so large phone clips fit upload limits more easily.
Aspect fixes
Use pad or crop when you need a standard 16:9 or square export.

Frequently Asked Questions

Quick answers about this tool—open a question to read more.

Resize video online — video resizer

What is a video resizer?

Video resizer features

How to resize a video online

Great for

Frequently Asked Questions

Video Upscaler

Compress Video

Mute Video

MOV to MP4 Converter

Speed Up Video