AVI Converter

Convert AVI to Any Video Format Online

AVI is the multimedia container Microsoft introduced in November 1992 as part of Video for Windows, and decades of camcorders, screen recorders, and old editing exports still write to it. It is dependable on a Windows desktop, but AVI files are usually much larger than a modern equivalent and they often won't open on phones, in web browsers, or when you try to upload them to a social platform. This converter re-wraps or re-encodes your AVI into whatever the destination actually speaks — MP4 for universal playback, MOV for Apple workflows, MKV or WebM for media libraries and the web, GIF for a short loop, or a plain MP3 if you only want the audio. Everything runs on our servers with no sign-up and no watermark.

How to Convert AVI to MP4 (or Any Format)

1. Upload Your AVI File: Drag and drop onto the page or click "Add Files" to pick clips from your computer. Batch is supported — drop in several AVI files and each one converts independently, so you can clear out a whole folder of legacy recordings in a single job.
2. Pick Video File Extension and Quality Preset: Set the output container under "Video File Extension" — MP4, MOV, MKV, WebM, GIF, and 30-plus more, or an audio extension such as MP3 to extract the soundtrack. Leave File Compression on the default "Very High (Recommended)" Quality Preset, or switch the bitrate mode to Constant Bitrate for predictable streaming sizes, Variable Bitrate for smaller files at equal quality, or Constant Quality to target a perceptual quality level directly.
3. Resize, Trim, or Tune Codec (Optional): Under Video resolution, keep the original, choose a Preset Resolution (2160p / 1440p / 1080p / 720p / 480p and down), scale by Resolution Percentage, or enter a custom Width × Height with aspect ratio locked. Under Trim, switch from Unchanged to Time Range and enter a start and duration to keep only the part you need. Advanced Options also expose the video codec (H.264, H.265/HEVC, VP9, AV1, MPEG-4, XviD, MJPEG) and audio codec (AAC, MP3, Opus, FLAC, AC3, PCM).
4. Convert and Download: Click Convert. Files process on our servers — no email, no sign-up, no watermark — then download each result individually or grab the whole batch as a single ZIP.

Popular AVI Conversions

• AVI to MP4 — the default: far smaller files that play on virtually every phone, browser, TV, and social platform
• AVI to MOV — for Final Cut Pro, iMovie, and other Apple QuickTime-based editing
• AVI to MKV — an open container that carries multiple audio tracks and subtitles for a media server
• AVI to WebM — royalty-free VP9 or AV1 for lightweight HTML5 web embeds
• AVI to GIF — turn a short clip into a silent looping animation with an adjustable palette
• AVI to MP3 — drop the video and keep just the audio track

Why Convert Away From AVI?

AVI's reputation for quality is real — it can even hold uncompressed or lightly compressed video — but that is exactly why the files are so heavy, and the format predates the streaming era. Modern containers pair efficient codecs with broad device support, so converting is usually about shrinking the file and making it open everywhere. Common reasons people move off AVI:

• It won't play on a phone or in a browser — iOS Photos, the Android gallery, and Safari, Chrome, Firefox, and Edge have no reliable built-in AVI playback. Re-wrapping to MP4 with H.264 plays natively on essentially every modern device.
• Social platforms reject or re-encode it — YouTube, Instagram, TikTok, X, and Facebook all process MP4 with H.264/AAC fastest and most predictably. Upload an AVI and you are at the mercy of a server-side re-encode that can soften the picture. Converting first puts you in control of the encode.
• The files are too big to send or store — because AVI leans on older, lighter compression, a clip can be several times larger than the same footage in MP4 with H.264, or smaller still with H.265 or AV1. Re-encoding, downscaling, or trimming brings most clips under an email or chat attachment cap.
• Editors and NLEs prefer MP4 or MOV — Premiere, DaVinci Resolve, Final Cut, and CapCut all import MP4 and MOV cleanly. Old DivX/XviD-era AVI files can stutter or refuse to import on a modern timeline.
• It is a Windows-first format — AVI grew up on Windows, and the further you get from a Windows desktop with the right codecs installed, the less dependable it is. MP4 carries no such baggage.

If your goal is only to make an existing AVI smaller without changing the container, use Compress MP4 on the converted file, or trim dead footage with Video Cutter before converting — trimming is the highest-leverage step on a long clip.

Codec vs. Container: What Actually Changes

A video file has two layers, and confusing them is the most common source of "why won't this play" headaches. The container is the wrapper — AVI, MP4, MOV, MKV, WebM — that holds the streams and tells a player how they fit together. The codec is the compression method for the picture and sound inside it — H.264, H.265, VP9, AV1 for video; AAC, MP3, Opus, AC3 for audio. A player can recognize a container yet still fail because it lacks the codec inside, which is why simply renaming a file extension never works.

When you convert, one of two things happens. If the AVI already holds a codec the target container accepts, the streams can be re-wrapped without re-encoding — a fast, lossless remux that just changes the box. More often an AVI carries an older codec like DivX or XviD that MP4 won't host, so the video is re-encoded to H.264 (or another codec you pick) during the convert step. Re-encoding is generational, but at a high Quality Preset or Constant Quality the difference is invisible in normal viewing. Resolution and bitrate are independent knobs: dropping 1080p to 720p, or capping the bitrate, are deliberate tradeoffs you make to hit a size target, not something the conversion forces on you.

AVI vs. MP4 at a Glance

Frequently Asked Questions

Why is my AVI file so much larger than an MP4?

AVI dates to 1992 and is commonly paired with older codecs — DivX, XviD, MPEG-4 Part 2, or even uncompressed video — that compress far less aggressively than the H.264, H.265, and AV1 codecs typically found in MP4. The container itself isn't the main cause; the codec inside it is. Re-encoding an AVI to MP4 with H.264 usually produces a noticeably smaller file at comparable quality, and choosing H.265 or AV1 shrinks it further. Downscaling the resolution or trimming dead footage reduces the size on top of that.

Will converting AVI to MP4 reduce the video quality?

It depends on what is inside the AVI. If the source codec is one MP4 already accepts, the streams can be remuxed into the MP4 container with no re-encoding and zero quality change. If the AVI holds an older codec like XviD, the video is re-encoded to H.264 or whichever codec you choose, which is technically generational loss — but at the default "Very High" Quality Preset, or with Constant Quality set to a high level, the result is visually indistinguishable from the source in normal viewing. Avoid downscaling the resolution unless you specifically want a smaller file.

Why won't my AVI file play on my iPhone, Android phone, or in a browser?

AVI is a Windows-first format, and iOS, Android, and the major browsers (Safari, Chrome, Firefox, Edge) do not include reliable built-in AVI playback the way they do for MP4. On a phone you'll often get an error or silent failure even when a desktop plays the same file. Converting to MP4 with H.264 video and AAC audio fixes this completely, since that combination plays natively across essentially every modern phone, browser, smart TV, and console.

Should I pick H.264, H.265, VP9, or AV1 when converting?

Choose H.264 if you don't know your audience — it has the widest hardware support and the lowest playback risk, and it is the safe default for sharing and social uploads. H.265 (HEVC) cuts the file size roughly in half at the same quality and is ideal when your viewers are on recent iPhones, modern Macs, Apple TV, or recent Android devices. VP9 and AV1 are royalty-free and well-suited to web embeds and streaming, with AV1 offering the best compression of the four; their main tradeoff is that software encoding is slower. You set this under the video codec dropdown in Advanced Options.

Can I extract just the audio from an AVI file?

Yes. Choose an audio extension such as MP3 (or AAC, FLAC, WAV, or M4A) under "Video File Extension" instead of a video container, and the converter outputs the soundtrack only, with no video. This is handy for pulling a song, a lecture, or an interview out of a recorded AVI. For the dedicated workflow, see AVI to MP3.

Is there a file size limit, and are my files private?

There is no fixed per-file cap. Conversion runs on our servers, so the practical limit is upload size and connection speed and your patience for large AVI uploads — multi-gigabyte files are routine, and if a very large file strains your device you can trim or downscale first. Because processing happens in your session on our servers, the files stay private; there is no account to create and nothing is kept after the job finishes.

How small can the converter make my AVI?

It depends on the source resolution, length, and how aggressively you compress, so there is no single number — but the levers are predictable. Re-encoding a typical standard-definition DivX-era AVI to MP4/H.264 at the default Quality Preset cuts the file to a fraction of the original, visually near-identical at the Very High preset for most content, and switching to H.265 or dropping the resolution a tier shrinks it further. To hit an exact target, set a Constant Bitrate or use the file-size controls, then trim any dead footage — on long clips, trimming saves more than any codec choice.