Question 1

Is this aspect ratio converter really free?

Accepted Answer

Yes. No account, no trial, no export cap and no watermark burned into the file you download. Convert as many clips as you like — the only real ceiling is how much memory your device has.

Question 2

Does my video get uploaded to a server?

Accepted Answer

No. The file is read from your disk with the browser's File API and re-encoded with WebCodecs on your own machine. If you want to check, open DevTools, switch to the Network tab and convert a clip: you will not see a single request carrying your video.

Question 3

Which formats can I put in, and what comes out?

Accepted Answer

MP4, MOV, WebM, MKV and AVI go in, as long as your browser can decode what is inside — that covers H.264, HEVC on most Macs, VP9 and AV1. What comes out is always an MP4 with H.264 video, which is the file TikTok, Instagram and YouTube all accept without arguing. The audio track is carried straight across whenever the container allows it.

Question 4

How large a video can I convert?

Accepted Answer

Up to 2 GB. Past roughly 500 MB it warns you first, because the output is assembled in memory: a 1 GB source is fine on a laptop with plenty of RAM and may not be on an older phone. Long 4K clips are the hardest case — choosing a 720p output makes a big difference there.

Question 5

Crop, pad or blur fill — which one should I pick?

Accepted Answer

Crop fills the new frame and throws the rest away: 16:9 to 9:16 discards about two thirds of the picture, which is exactly why you can drag the preview to say what stays. Pad and blur fill keep every pixel and fill the leftover space instead — flat colour for a clean look, a blurred copy of the frame for the style Reels and Shorts made standard. The tool shows you the percentage before you commit to a crop.

Question 6

Will converting lose quality?

Accepted Answer

The picture is decoded and encoded again, so yes, it is lossy — but the bitrate is set generously and capped at what the source already carried, so the change of shape is meant to be the only thing you can see. Your device's hardware encoder does the work through WebCodecs, which is why a one-minute clip takes seconds rather than minutes.

Question 7

Can it fill in the missing picture instead of cropping or padding?

Accepted Answer

Not here, and not in any browser tab: the pixels outside the original frame were never recorded, so extending them means inventing them. That is what an AI video model is for — it generates in 9:16, 16:9 or 1:1 natively rather than reshaping something that was shot the other way round. If a full vertical frame is what you actually need, it is better to generate it than to crop into it.

Question 8

Can I convert several videos at once, or on my phone?

Accepted Answer

One clip at a time, on purpose: decoding and encoding are memory-hungry, and a browser tab running a batch is the fastest way to crash it. When one is done, press "Convert another". It does work on phones — recent iOS and Android Chrome both ship WebCodecs — but keep clips short there, and keep the tab in the foreground while it runs.

Change Video Aspect Ratio

Video Trimmer

Video Merger

Video to GIF

Video Compressor

Add Audio to Video

Mute Video

Video Frame Extractor

Last Frame Extractor

Gemini Video Watermark Remover

How to change a video's aspect ratio

Drop in your video

Pick the shape and the fit

Convert and download

Frequently Asked Questions

Is this aspect ratio converter really free?

Does my video get uploaded to a server?

Which formats can I put in, and what comes out?

How large a video can I convert?

Crop, pad or blur fill — which one should I pick?

Will converting lose quality?

Can it fill in the missing picture instead of cropping or padding?

Can I convert several videos at once, or on my phone?

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