Question 1

How does the video compressor reduce the file size?

Accepted Answer

It decodes and re-encodes the video using a target bitrate determined by the selected quality setting, the video resolution, and the output codec. The audio is handled separately.

Question 2

What do the three quality settings mean?

Accepted Answer

High quality uses the highest target bitrate and will generally produce the largest output. Balanced uses a middle setting. Smallest uses the lowest target bitrate, trading more visual quality for a potentially smaller file.

Question 3

Can I choose an exact output size or bitrate?

Accepted Answer

No. The page provides three quality presets rather than an exact bitrate or target file size. The final size cannot be predicted precisely before compression.

Question 4

Will compression always make my video smaller?

Accepted Answer

No. The target bitrate is calculated without reference to the original bitrate. If the source is already efficiently compressed or uses a lower bitrate, the result could be similar in size or even larger.

Question 5

Will compression reduce the video quality?

Accepted Answer

Yes. The video is re-encoded using lossy compression. The Smallest setting is more likely to produce visible quality loss, while High quality retains more information.

Question 6

Will the resolution, aspect ratio, frame rate, or duration change?

Accepted Answer

No. This page does not request resizing, cropping, frame-rate conversion, or trimming. It keeps the original display dimensions, aspect ratio, frame rate, and duration.

Question 7

Which video formats can I compress?

Accepted Answer

The page is configured for MP4 and M4V, MOV, WebM, MKV, and MPEG-TS files, including.ts,.mts, and.m2ts. The file must contain a readable video track.

Question 8

Will the compressed file keep the same format?

Accepted Answer

MP4, M4V, MOV, WebM, and MKV inputs use their corresponding output container. MPEG-TS and other readable video inputs without a matching output target are saved as MP4.

Question 9

Which video codec will the compressed file use?

Accepted Answer

The codec depends on the output format and what your browser can encode. MP4, MOV, and MKV prefer H.264 when it is available. WebM tries supported WebM codecs in the order VP9, AV1, and VP8. The original codec is not guaranteed to be retained.

Question 10

What happens to the audio?

Accepted Answer

Compatible audio tracks are copied without re-encoding. If an audio codec is incompatible with the output container, the audio is re-encoded using a high-quality setting. Videos without audio can also be compressed.

Question 11

Are multiple video and audio tracks preserved?

Accepted Answer

The conversion pipeline attempts to process all supported video and audio tracks. If a track uses a codec the browser cannot decode or cannot encode for the output format, the conversion stops and displays an error rather than silently returning a file missing that track.

Question 12

Are subtitles, transparency, and metadata preserved?

Accepted Answer

Embedded subtitle tracks are not preserved, and video transparency is discarded. Descriptive metadata is copied where the output format supports it. Container-specific raw metadata is removed when the output container changes.

Question 13

Is there a file-size, duration, or resolution limit?

Accepted Answer

The page does not impose a fixed limit. However, the completed output is assembled in browser memory, so very large, long, or high-resolution videos can exceed the resources available on the device.

Question 14

Why might a video fail to compress?

Accepted Answer

Compression can fail if the file does not contain a video track, the browser cannot decode one of its audio or video codecs, or the browser cannot encode a compatible codec for the selected output container.

Compress video files

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