Step 1: Transfer your M4V files using the button above or by slide and deposit.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Retrieve your converted MP4 files.
M4V to MP4 Conversion FAQ
How do I re-encode M4V to MP4 without losing video quality?
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Upload your M4V file and the converter runs a CRF-based re-encode targeting visually-lossless MP4 output (CRF 18 by default, lower values = larger file / higher quality). The codec is chosen to match the MP4 container — H.264 for broad-compat MP4, H.265 for size-efficient MKV, VP9 for WebM, AV1 for newer pipelines. Structurally an M4V is an MP4 — H.264 or HEVC with AAC — with optional Apple FairPlay DRM and iTunes chapter metadata. Almost every MP4 in the wild is H.264 video with AAC audio; the container also legally holds HEVC, AV1 and VP9.
Can M4V be converted to MP4 without re-encoding the video?
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Yes, and it is the fast path. M4V and MP4 share the same underlying box structure, so the video and audio streams are copied across byte-for-byte and only the container wrapper is rewritten. Nothing is decoded and nothing is re-compressed, so a feature-length file finishes in under a minute instead of half an hour, with output quality identical to the source. M4V is Apple’s variant of MP4, used by iTunes and the Apple TV app for films and TV episodes. MP4 is ISO/IEC 14496-14, standardised in 2001 and derived from the same QuickTime box layout MOV uses.
My M4V has several audio tracks — do they all survive into the MP4?
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Not dependably. M4V stores multiple audio streams as first-class tracks, but MP4 playback support past the first track is inconsistent, so most players will only ever expose one. Choose the track you actually want before converting; the others are better extracted to their own files than left in a container that hides them. M4V keeps chapter markers, artwork and subtitle tracks in the shape the Apple TV app expects, which plain MP4 often loses. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
Why does my M4V file fail to convert to MP4?
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Almost always DRM. Some M4V files are encrypted at the bitstream level by the store or software that issued them, and an encrypted stream cannot be decoded by us or by anything else without the licence key. Files you recorded, exported or downloaded unprotected convert normally; a licensed purchase will not, and no converter can honestly promise otherwise. DRM-protected M4V purchases cannot be converted by anything; only unprotected M4V files are convertible, and non-Apple players often need the extension renamed.
Will the MP4 play in a browser when the M4V would not?
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Yes, and that is usually the whole reason for the conversion. An M4V embedded in a web page either shows a broken player or forces a download, because browsers ship no decoder for it. MP4 plays inline through the native HTML5 video element with no plugin and no external application. MP4 is the safest possible delivery target — every phone, browser, console, editor and Smart TV built in the last decade plays it without extra software.
Which video codec does the MP4 output use?
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It depends on the MP4 container. MP4 defaults to H.264 for the broadest playback support across phones, browsers, and Smart TVs. MKV defaults to H.265 / HEVC for roughly half the file size at equivalent quality. WebM defaults to VP9. The advanced options expose explicit codec choice if you need to override.
Will my audio track survive M4V to MP4 conversion?
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Yes. When M4V and MP4 share an audio codec (e.g. both carry AAC), audio is re-muxed with no re-encode — bit-identical. When the codecs differ, audio is transcoded to AAC / Opus / Vorbis depending on what the MP4 container supports. Multi-track audio (commentary, alternate languages) is preserved.
Can I keep the original framerate when converting M4V to MP4?
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By default yes — a 24fps M4V stays 24fps in MP4; a 60fps M4V stays 60fps. If you need to change rate (e.g. interlaced 29.97 → progressive 30, or 60 → 30 for upload limits), the framerate option handles 3:2 pulldown, deinterlacing, and frame-blending in the same encode pass.
How much will the file size change going from M4V to MP4?
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Same-codec re-mux (M4V H.264 → MP4 H.264 just changing container): nearly identical size. Codec change can swing dramatically: H.264 → H.265 typically halves the file at the same visual quality; VP9 is roughly comparable; AV1 cuts another 20-30% but is slower to encode.
Will the MP4 file play on iPhone, Android, and Smart TVs?
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MP4 / H.264 plays natively on every modern device. MOV / H.264 plays on Apple devices and most TVs but not always on older Android. MKV needs VLC on iOS. WebM is browser-first. The advanced options include a "device compatibility" preset that picks the safest MP4 codec / container for your target.
How long does converting a 1-hour M4V video to MP4 take?
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Same-codec re-mux is near-instant — 30 to 60 seconds for a 1-hour file. A full codec re-encode runs at roughly 0.3-0.7x source duration on our GPU pipeline, so a 1-hour M4V → MP4 finishes in 18-40 minutes depending on resolution and target codec.
What is the maximum resolution supported for M4V to MP4?
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Up to 8K (7680×4320) on Premium plans. Free conversions are capped at 4K (3840×2160) by the per-file size limit. HDR metadata (HDR10, HDR10+, Dolby Vision when present) is carried through where both M4V and MP4 containers support it.
