Step 1: Provide your M4V files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted MP4 files.
M4V to MP4 Conversion FAQ
How do I convert M4V to MP4 without re-encoding the video stream?
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When the M4V and MP4 containers can both carry the same codec (H.264, H.265, VP9, AV1), the converter falls back to a remux: the elementary streams are copied byte-for-byte into the MP4 container and only the wrapper changes. A remux of a 1 GB M4V into MP4 typically finishes in 5-15 seconds with zero quality loss. 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.
Will multi-track audio survive M4V to MP4 conversion?
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Yes — every audio track in the M4V (director commentary, alternate languages, descriptive audio) is preserved in the MP4 when the target container supports multi-stream audio. MKV and MOV handle unlimited audio tracks; MP4 supports many but some hardware players only see track 1; WebM is capped at one Opus / Vorbis track.
Are subtitle tracks preserved when converting M4V to MP4?
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Soft subtitles (selectable tracks) survive when MP4 can carry them: MKV holds SRT, ASS, SSA, PGS, VobSub natively; MP4 only holds mov_text (a stripped-down format). Converting an MKV with ASS styled subs to MP4 will typically downgrade them to mov_text or burn them in. Hardsubs (burned into the video) carry over regardless.
Does M4V to MP4 keep chapter markers / DVD-style navigation?
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Chapter metadata transfers between M4V and MP4 whenever both containers support a chapter atom (MKV, MP4, MOV). WebM stores chapters in a Matroska-compatible block, so MKV <-> WebM chapters round-trip cleanly. AVI has no chapter spec at all, so an AVI source arrives with no chapters to carry across and an AVI target cannot store the ones it was handed; add markers manually afterwards if you need them.
What about MKV attachments (fonts, cover art) when going M4V to MP4?
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MKV is the only mainstream container that stores arbitrary attached files (TTF fonts for ASS subs, JPG cover art, fan-translated PDF inserts). Going from M4V to MP4 drops these attachments when MP4 is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep M4V as a backup if you depend on attached fonts.
Which codec does the MP4 output use by default?
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The default codec is chosen to match the MP4 container conservatively: MKV defaults to H.265 (HEVC) for better compression; MP4 defaults to H.264 for the widest device support; WebM defaults to VP9; AVI uses MPEG-4 ASP (DivX/Xvid lineage). Override via the advanced codec dropdown — AV1 is available for MKV / WebM where you want maximum compression and can wait through the encode.
How does HDR (HDR10, Dolby Vision) survive M4V to MP4?
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HDR static metadata (HDR10 mastering display values, max content light level) carries through to MP4 when both containers and the chosen codec support it (HEVC, AV1 in MKV / MP4). Dolby Vision is more fragile — DV profile 5 / 7 / 8.1 in M4V commonly survives only into MKV with HEVC; converting to an MP4 container that does not carry the DV layer flattens to HDR10.
Will the M4V to MP4 converter keep variable framerate (VFR)?
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MKV and WebM record real per-frame timestamps and handle VFR natively, so M4V VFR survives into an MP4 of those formats with no resampling. MP4 nominally stores timestamps too but some players assume CFR; the converter exposes a "force CFR" toggle that resamples VFR M4V to 24 / 30 / 60 fps MP4 for problematic targets.
