Video Converter for MP4, WebM, MOV, and More

Q: How do I change a video's codec?

Choose a format, then pick the new codec under Video codec, for example MP4 with h264 instead of h265. To keep the container and only swap the codec, select the same format as the source. H.264, H.265, VP8, VP9 and AV1 are encoded at CRF 23 unless you change it.

Q: Does converting reduce quality?

copy leaves the streams untouched. Re-encoding at usual settings loses some detail. H.264 at CRF 18 usually looks nearly identical to the source, and 23 is the default here. Higher values save space, and the loss shows first in fast motion and dark scenes.

Q: How do I set the quality of an AVI, MPEG or WMV file?

Their default codecs (mpeg4, mpeg2video, wmv2) are controlled with Video bitrate instead of CRF. Enter a value such as 8000k for 1080p, or choose h264 for AVI, which supports CRF.

Q: Which settings suit many devices?

MP4 with the defaults h264 and aac is a widely supported starting point; fast start is added automatically. Check the supported resolution and frame rate on older devices.

Changing a video's container and codec

Choose an output container such as MP4, WebM, MOV or MKV, then select compatible video and audio codecs. Adjust resolution, frame rate, quality or bitrate for the intended destination. A container name alone does not determine whether a device can play the result. Convert a representative clip first when testing a new format or encoder setting.

Cost: Free to use. File size and usage limits apply.

How to convert a video

Upload one video
Click Choose files or drop a file on the preview. MP4, M4V, MOV, MKV, WebM, AVI, MPEG/MPG and OGV files up to 200 MB are accepted, one video per job. Videos you uploaded or created in other tools are listed under Uploads.
Pick the output format first
Under 1. Format, choose MP4, WebM, MOV, MKV, AVI, FLV, WMV, MPEG or OGV. Every click resets Video codec and Audio codec to that format's defaults, so change the codecs afterwards.
Check the codecs
Under 2. Codecs, both menus list the codecs offered for the chosen format. copy keeps a stream as it is; none in Audio codec removes the sound.
Adjust size and quality if needed
Open Optional resize for Resolution, FPS, CRF, Video bitrate and Audio bitrate. If you change nothing there, the video keeps its resolution and frame rate, and H.264, H.265, VP8, VP9 and AV1 are encoded at CRF 23.
Convert and download
Click Convert video. The result card shows the file name and new size above Download. AVI, WMV, FLV and MPEG results often don't play in the browser preview; check them in a desktop player.

Which format to choose

MP4: H.264 + AAC

A widely supported starting point for browsers, phones, TVs and editing apps. Fast start is always added, so playback can begin before the download finishes. h265 can use less data at similar quality but plays in fewer places; mpeg4 only helps very old players.

WebM: VP9 + Opus

Made for web pages. VP9 is the better default; pick vp8 only for old software. av1 can use fewer bits at comparable quality, depending on the source and settings, but encodes slower.

MOV: H.264 + AAC

The QuickTime container used by Apple apps. With 4:2:2 encoder input, prores writes 10-bit ProRes 422 HQ for editing; 4:4:4 or alpha input selects 4444. Detailed 1080p footage can exceed 1 GB per minute. pcm_s16le stores uncompressed audio.

MKV: H.265 + Opus

Accepts almost any codec. The default re-encodes to H.265, which is slow on long clips. Set both codecs to copy to rewrap compatible H.264 or H.265 streams without re-encoding instead. av1 can use fewer bits at comparable quality, depending on the source and settings, but encodes slower.

AVI: MPEG-4 + MP3

For older players and editing programs. h264 can use fewer bits for a comparable picture, depending on the source and settings. mjpeg stores every frame as a JPEG image: large files, but easy to cut frame by frame.

FLV, WMV and MPEG

Legacy formats for software that demands them. FLV uses H.264 + AAC (or Sorenson flv1), WMV uses WMV2 + WMA v2 with wmv1 video and mp3 audio also available, and MPEG writes MPEG-2 + MP2 program streams (or MPEG-1) for DVD-era tools.

OGV: Theora + Vorbis

An open format for older open-source players. The defaults encode Theora video and Vorbis audio at fixed quality levels. opus audio is also available; copy preserves compatible existing streams without re-encoding.

Settings explained

Video codec: h264 is widely supported. h265 can reach similar quality at a lower bitrate but isn't supported by every browser. H.265 in MP4 and MOV is written in the form Apple players expect. Check codec and resolution support on the target device.
copy: Copies the stream without re-encoding. If the source codec doesn't fit the new format, or you set Resolution, FPS or Video bitrate, the tool re-encodes with the format's default codec instead.
Audio codec: aac suits MP4, MOV and FLV, opus suits WebM and MKV, mp3 suits AVI. flac (MKV) and pcm_s16le (MOV, AVI) are lossless and large. none removes the sound.
Resolution: Original keeps the source size. Presets fit the video into a frame while keeping its aspect ratio: 360p = 640 × 360 px, 480p = 854 × 480 px, 720p = 1280 × 720 px, 1080p = 1920 × 1080 px, 1440p = 2560 × 1440 px, 4k = 3840 × 2160 px. A preset larger than the source upscales without adding detail. Choose Custom for exact dimensions, or Resize Video for more sizing options.
Width and Height (Custom): Values in px. Fill in one field to keep the aspect ratio: Width 720 turns a 1080 × 1920 px phone video into 720 × 1280 px. Filling both forces that exact frame. Odd values are rounded down to even numbers; the maximum is 7680 × 4320 px.
FPS: Output frame rate from 1 to 120 fps. Leave it empty to keep the source rate. Halving 60 fps to 30 fps lowers the bitrate the encoder needs; raising the frame rate only repeats frames.
CRF: Constant quality for h264, h265, vp8, vp9 and av1, default 23. Lower values mean better quality and larger files. Use 0–51 for H.264 and H.265 and 0–63 for VP8, VP9 and AV1. Other codecs are controlled with Video bitrate.
Video bitrate: Target data rate, for example 4000k for 4,000 kbps or 4M for 4 Mbps. With H.264, H.265, VP8, VP9 and AV1, entering a bitrate replaces the CRF quality target. For mpeg4, mpeg2video, mpeg1video, wmv1, wmv2, flv1 and mjpeg it is the quality control: try 8000k for 1080p or 4000k for 720p, then check detail and file size. ProRes and Theora use their own fixed quality level.
Audio bitrate: For example 128k or 192k. Leave it empty for the encoder's default. Lossless flac and pcm_s16le don't use a bitrate, and vorbis in OGV uses a fixed quality level.

Changing the container without re-encoding

Set Video codec and Audio codec to copy and the tool moves compatible existing streams into the new container. This avoids re-encoding and keeps the copied picture and sound identical. Total file size also depends on the container, retained tracks and metadata.

Stream copy works when the source codecs are allowed in the target format. Typical cases: H.264 or H.265 video with AAC audio from a phone MOV into MP4 or MKV, or VP9 or AV1 with Opus from WebM into MKV. Otherwise the stream is re-encoded with the format's default codec: copy on H.264 for WebM gives VP9.

Each re-encode loses a little detail, so start from the original file rather than from an earlier conversion.

Formats and limits

Input formats: MP4, M4V, MOV, MKV, WebM, AVI, MPEG/MPG, OGV
Output formats: MP4, WebM, MOV, MKV, AVI, FLV, WMV, MPEG, OGV
Maximum file size: 200 MB per video
Files per job: 1
Tracks kept: One video and one audio track. If the source has several audio tracks, for example languages in an MKV, only one is kept, normally the one marked as default. A text subtitle track is kept only in WebM and MKV output.
Metadata: Title, comment and similar tags are carried over. To remove metadata such as GPS location, use Compress Video, which strips metadata by default.
Processing: On our servers with FFmpeg; the file isn't sent to any outside service. A job can run for up to 15 minutes, so AV1 or H.265 encodes of long or 4K clips may not finish.
Watermark: None
Storage: Uploads and results are deleted automatically after 48 hours for guests and after 30 days for free accounts. Paid plans can keep files longer.

Frequently asked questions

How do I change a video's codec?

Choose a format, then pick the new codec under Video codec, for example MP4 with h264 instead of h265. To keep the container and only swap the codec, select the same format as the source. H.264, H.265, VP8, VP9 and AV1 are encoded at CRF 23 unless you change it.

Why is the converted file larger than the original?

Usually because of H.265 converted to H.264 at CRF 23, ProRes, FLAC or PCM, or a Resolution preset that upscales a smaller video. Raise CRF, keep an efficient codec or use Compress Video when size is the goal.

Does converting reduce quality?

copy leaves the streams untouched. Re-encoding at usual settings loses some detail. H.264 at CRF 18 usually looks nearly identical to the source, and 23 is the default here. Higher values save space, and the loss shows first in fast motion and dark scenes.

How do I set the quality of an AVI, MPEG or WMV file?

Their default codecs (mpeg4, mpeg2video, wmv2) are controlled with Video bitrate instead of CRF. Enter a value such as 8000k for 1080p, or choose h264 for AVI, which supports CRF.

Which settings suit many devices?

MP4 with the defaults h264 and aac is a widely supported starting point; fast start is added automatically. Check the supported resolution and frame rate on older devices.