Step 1: Supply your AVI files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted MP4 files.
AVI to MP4 Conversion FAQ
What does the AVI to MP4 converter do?
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AVI is a legacy container, often poorly supported on modern devices. Converting to MP4 rewraps the video with a current codec (H.264 / H.265 / VP9) for broad browser, phone, and TV compatibility.
Will resolution and frame rate be preserved in the MP4?
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Yes. AVI → MP4 keeps resolution, frame rate, and aspect ratio unchanged by default. To change them, use the Resize or Speed tool on the result.
Will the AVI play smoothly on modern devices after converting to MP4?
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Yes. Legacy AVI files often fail to play in modern browsers and on iOS / Android. MP4 uses widely supported codecs that play natively on phones, tablets, smart TVs, and every modern browser.
Will the converted MP4 be a different size than the AVI?
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Modern codecs compress better, so MP4 from a legacy AVI is typically 30-60% smaller at equivalent quality. Conversions in the opposite direction can grow the file.
Is there a file-size limit when converting AVI to MP4?
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Anonymous uploads are capped at a generous default; signed-in free accounts get a higher cap, and Pro accounts have no per-file limit. Browser memory is usually the practical constraint long before our server-side limits kick in.
Can I batch-convert several AVI files to MP4 at once?
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Yes. Drop or pick multiple AVI files in one upload — the converter processes them in parallel and returns a ZIP of the MP4 results. There is no need to repeat the upload step per file.
What happens to my AVI files after the conversion?
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Uploaded files and MP4 outputs are auto-deleted after a short retention window. We do not inspect, share, or train on user files. Direct download links are time-limited and tied to your session.
Will my MP4 play on phones, tablets, and TVs?
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Yes — MP4 uses modern codecs that play natively on iOS, Android, Smart TVs, game consoles, and every modern browser.
Do I need to install software to convert AVI to MP4?
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No. The converter runs entirely in your browser plus our cloud — no plugin, no install, no admin rights. It works on Windows, macOS, Linux, ChromeOS, iOS, and Android.
Do I need an account to convert AVI to MP4?
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No. AVI to MP4 conversion is free and works without an account. Signing in unlocks higher file-size caps, batch history, and API access.
Is there an API for AVI to MP4 conversion?
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Yes. Every conversion this site offers is also exposed via a JSON API — see /api/ for endpoints, authentication, and rate limits. AVI to MP4 is one of the supported pairs.
What if my AVI fails to convert to MP4?
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Failures are usually caused by corrupted source files or unsupported AVI variants. Re-export from the original app and try again; if it still fails, the contact page forwards the file to support so we can diagnose.