Convert AVI to MP4 Online for Free
Turn an AVI recording into an MP4 you can edit or share.
Drop your AVI recording here
or choose a local file or import from a URL
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How to convert AVI to MP4
1. Select the AVI recording
Choose the .avi from your camera or capture folder. Play a moment with visible movement and a familiar voice so you have a reference for the finished file.
2. Choose a resolution
Use Original to keep the frame dimensions. Choose a smaller height for a review copy if the lettering and faces will still be clear on the recipient’s screen.
3. Download and check the MP4
Select Convert AVI to MP4. Open the saved file in the player or editor you are preparing it for. Compare the same movement and words there.
When to convert AVI to MP4 for an editor
An AVI that plays in a desktop player can still import into an editor with only sound or only picture. AVI is the container. A camera recording may use Motion JPEG, while a tape transfer may contain DV. Open the source in the editor’s clip preview and check which streams it recognizes before changing export settings.
| What you can reproduce | What to try |
|---|---|
| The picture moves in a desktop player but the editor imports only sound | Check the video codec in the source details. Try an MP4 working copy and open it in the editor. |
| Both tracks play in the editor’s source preview, but only sound reaches the timeline | Check whether the video source track is enabled for insertion. Add the clip again with both tracks selected. |
| The original camera clip plays silently everywhere | Look for a recorded audio track and try a scene you remember having sound. |
| A different voice plays in the MP4 | Check which soundtracks exist in the AVI. Prepare the desired mix before converting if the source has several tracks. |
If both streams play in the clip preview but only audio appears on the timeline, check the video track and the insertion mode. Try inserting the same clip into an empty sequence with a video track enabled. If the image is missing from the source preview as well, convert AVI to MP4 and test the H.264 copy in that editor.
How to convert AVI to MP4 at the original resolution
Choose Original for the first editing copy. A small camera clip will look bigger when a player stretches it across a laptop screen. Compare the source and the export at the same display size before drawing conclusions about quality. Look for details that matter to this edit, such as the letters on the front of a building or a hand moving across a face. Check the edge of the frame as well as the centre.
The converter targets H.264 video and AAC audio for MP4. Compatible streams may be repackaged. Other recordings need decoding and encoding, especially when you choose a smaller resolution. If you want to convert AVI to MP4 for sharing, decide how much detail your audience actually needs. Keep the capture itself if you expect to edit it again. Original resolution describes the frame size and cannot guarantee a bit-for-bit copy.
A long AVI made from tape can take much more space than a short video from a pocket camera. Running time, source codec, frame dimensions and movement all matter. If you convert AVI to MP4 for an upload allowance, measure the downloaded file. When it remains too large, prepare a smaller viewing copy or trim the footage to the part the recipient asked for. Keep the uncut recording separately so the next edit need not start with a reduced copy.
Check picture, voice and timing in the saved MP4
Put the original and the downloaded MP4 in separate folders. Pick a point near the start where you can see someone clap or shut a door. Compare the moment of contact with the sound in each file, then repeat the check near the end. This helps distinguish a delay already present in the original from a problem that appears only after export. Human speech alone can be hard to judge if the speaker is far from the camera.
When you convert AVI to MP4 to fix an import, test the actual edit you need to make. Import the downloaded file as a new clip, place it in a short sequence, play it and listen. A thumbnail says little about later frames. A waveform shows that audio data exists but cannot tell you whether it contains the intended voice. Before sending the final cut, listen to the last sentence from the exported sequence itself.
Frequently asked questions about AVI to MP4 conversion
Can I convert AVI to MP4 free without signing up?
Yes. Select your AVI, choose a resolution and download the result in your browser. Local files are processed on your device. Save the MP4 before closing the tab so you can open the same copy in your editing application.
Will an AVI convert if the browser preview is blank?
A blank preview can mean that the browser player lacks the video decoder. Try the AVI to MP4 converter with the complete local file, then open the downloaded MP4 in a separate player. If it also stops, check the same passage in the source.
Does Original preserve the picture quality?
Original keeps the source dimensions. AVI to MP4 conversion may reuse compatible streams; resizing or changing the video codec requires encoding. Compare motion and fine text at the same display size.
Why is my AVI silent in an editor but audible in a player?
The two programs may support different audio codecs. Check that the source preview in the editor really is silent, and that the output device and track are enabled. If only the editor cannot decode the sound, try importing the converted MP4 as a new clip.
Can I just rename an .avi file to .mp4?
Renaming the file leaves the AVI structure and its streams unchanged. A player that recognises the data may still open it. To give someone a file that an MP4 editor can actually import, export an MP4 and check it in that editor.
Which AVI codecs can I try?
AVI can contain DV, Motion JPEG, Xvid and other codecs. Whether you can convert AVI to MP4 depends on whether the engine can read the particular streams in your file. A working AVI from a different camera may use a different codec.
How do I keep the full frame?
Select Original, then inspect the four edges of the saved video. In a widescreen project, use a setting that fits the whole image if you need to preserve everyone in the shot. Cropping a clip to fill the project can remove people at the edges.
Will a separate subtitle file travel with my MP4?
Selecting an AVI gives the converter one file. Captions already visible in the picture remain part of the picture. Keep any separate subtitle file and add it explicitly in a subtitle or editing workflow if viewers need selectable text.
Can I choose an alternate soundtrack?
The AVI to MP4 converter has no language or track selector. Choose a source with the soundtrack you need, or prepare the mix in an editor first. Check a passage with dialogue in the saved file.
Which download links will open?
Use a direct HTTPS address for the media when its host allows your browser to read it. A gallery or sign-in page is usually a viewer rather than a video file. Download the AVI to your device first if that is the only link you have.
Is a smaller MP4 guaranteed?
No fixed ratio applies. A large, lightly compressed capture can shrink considerably, while an already compact AVI may yield a similar or larger output. Compare the actual file sizes and check the picture at the intended display size before sharing.
What if the AVI stops before the last scene?
Check the same point in the source and try seeking past it. If the original copy on the camera or capture drive continues, copy it again and export from the complete file. A change of format cannot supply footage missing from every surviving source.