免费转换 M4A 文件
专业的 M4A 文件转换工具
将您的文件拖放到这里
或点击浏览文件
支持的格式
以高质量在所有主要文件格式之间转换
常见格式
MPEG-1音频层III - 全球最通用的音频格式，使用有损压缩将文件大小减少90%，同时保持出色的感知质量。非常适合音乐库、播客、便携设备以及任何需要广泛兼容性的场景。支持32-320kbps的比特率。自1993年以来成为数字音乐的标准，几乎可以在每个设备和平台上播放。
Waveform Audio File Format - uncompressed PCM audio providing perfect quality preservation. Standard Windows audio format with universal compatibility. Large file sizes (10MB per minute of stereo CD-quality). Perfect for audio production, professional recording, mastering, and situations requiring zero quality loss. Supports various bit depths (16, 24, 32-bit) and sample rates. Industry standard for professional audio work.
Ogg Vorbis - 开源有损音频编码器，提供与MP3/AAC相当的质量，且比特率相似。无专利和许可限制。与MP3在相同质量下文件大小更小。用于游戏、开源软件和流媒体。支持可变比特率（VBR），以获得最佳质量。非常适合需要免费编码器和良好质量的应用。媒体播放器和平台的支持不断增加。
Advanced Audio Coding - successor to MP3 offering better quality at same bitrate (or same quality at lower bitrate). Standard audio codec for Apple devices, YouTube, and many streaming services. Supports up to 48 channels and 96kHz sample rate. Improved frequency response and handling of complex audio. Perfect for iTunes, iOS devices, video streaming, and modern audio applications. Part of MPEG-4 standard widely supported across platforms.
无损音频压缩编码器 - 在不损失任何质量的情况下压缩音频40-60%。完美保留原始音频的逐位精度。开放源代码格式，无专利或许可费用。支持高分辨率音频（192kHz/24-bit）。非常适合归档音乐收藏、音响爱好者听音和质量至关重要的场景。广泛支持媒体播放器和流媒体服务。质量与文件大小之间的理想平衡。
MPEG-4 Audio - AAC or ALAC audio in MP4 container. Standard audio format for Apple ecosystem (iTunes, iPhone, iPad). Supports both lossy (AAC) and lossless (ALAC) compression. Better quality than MP3 at same file size. Includes metadata support for artwork, lyrics, and rich tags. Perfect for iTunes library, iOS devices, and Apple software. Widely compatible across platforms despite Apple association. Common format for purchased music and audiobooks.
Windows Media Audio - Microsoft's proprietary audio codec with good compression and quality. Standard Windows audio format with native OS support. Supports DRM for protected content. Various profiles (WMA Standard, WMA Pro, WMA Lossless). Comparable quality to AAC at similar bitrates. Perfect for Windows ecosystem and legacy Windows Media Player. Being superseded by AAC and other formats. Still encountered in Windows-centric environments and older audio collections.
无损格式
Apple Lossless Audio Codec - Apple's lossless compression reducing file size 40-60% with zero quality loss. Perfect preservation of original audio like FLAC but in Apple ecosystem. Standard lossless format for iTunes and iOS. Supports high-resolution audio up to 384kHz/32-bit. Smaller than uncompressed but larger than lossy formats. Perfect for iTunes library, audiophile iOS listening, and maintaining perfect quality in Apple ecosystem. Comparable to FLAC but with better Apple integration.
Monkey's Audio - 高效的无损压缩，达到比FLAC更好的压缩比（通常为原始文件的55-60%）。完美保留质量，零损失。免费格式，开放规范。压缩/解压缩速度比FLAC慢。受到音响爱好者社区的欢迎。与FLAC相比，播放器支持有限。非常适合在最大空间节省的情况下进行归档，同时保持完美质量。最适合存储空间至关重要而处理速度不重要的场景。
WavPack - hybrid lossless/lossy audio codec with unique correction file feature. Can create lossy file with separate correction file for lossless reconstruction. Excellent compression efficiency. Perfect for flexible audio archiving. Less common than FLAC. Supports high-resolution audio and DSD. Convert to FLAC for universal compatibility.
True Audio - lossless audio compression with fast encoding/decoding. Similar compression to FLAC with simpler algorithm. Open-source and free format. Perfect quality preservation. Less common than FLAC with limited player support. Perfect for audio archiving when FLAC compatibility not required. Convert to FLAC for broader compatibility.
Audio Interchange File Format - Apple's uncompressed audio format, equivalent to WAV but for Mac. Stores PCM audio with perfect quality. Standard audio format for macOS and professional Mac audio applications. Supports metadata tags better than WAV. Large file sizes like WAV (10MB per minute). Perfect for Mac-based audio production, professional recording, and scenarios requiring uncompressed audio on Apple platforms. Interchangeable with WAV for most purposes.
现代格式
Opus音频编码器 - 现代开源编码器（2012年）在6kbps到510kbps的所有比特率下提供最佳质量。对语音和音乐表现出色。现代编码器中延迟最低，非常适合VoIP和实时通信。在相同比特率下优于MP3、AAC和Vorbis。被WhatsApp、Discord和WebRTC使用。非常适合流媒体、语音通话、播客和音乐。正在成为互联网音频的通用音频编码器。
{format_webm_desc}
Matroska Audio - audio-only Matroska container supporting any audio codec. Flexible format with metadata support. Can contain multiple audio tracks. Perfect for audio albums with chapters and metadata. Part of Matroska multimedia framework. Used for audiobooks and multi-track audio. Convert to FLAC or MP3 for universal compatibility.
遗留格式
MPEG-1音频层II - MP3的前身，用于广播和DVD。在高比特率下质量优于MP3。DVB（数字电视）和DVD-Video的标准音频编码器。压缩效率低于MP3。非常适合广播应用和DVD制作。作为遗留格式正在被AAC取代，仍在数字电视和视频制作工作流程中遇到。
Dolby Digital (AC-3) - surround sound audio codec for DVD, Blu-ray, and digital broadcasting. Supports up to 5.1 channels. Standard audio format for DVDs and HDTV. Good compression with multichannel support. Perfect for home theater and video production. Used in cinema and broadcast. Requires Dolby license for encoding.
Adaptive Multi-Rate - speech codec optimized for mobile voice calls. Excellent voice quality at very low bitrates (4.75-12.2 kbps). Standard for GSM and 3G phone calls. Designed specifically for speech, not music. Perfect for voice recordings, voicemail, and speech applications. Used in WhatsApp voice messages and mobile voice recording. Efficient for voice but inadequate for music.
Sun/NeXT Audio - simple audio format from Sun Microsystems and NeXT Computer. Uncompressed or μ-law/A-law compressed audio. Common on Unix systems. Simple header with audio data. Perfect for Unix audio applications and legacy system compatibility. Found in system sounds and Unix audio files. Convert to WAV or MP3 for modern use.
{format_mid_desc}
RealAudio - legacy streaming audio format from RealNetworks (1990s-2000s). Pioneered internet audio streaming with low-bitrate compression. Obsolete format replaced by modern streaming technologies. Poor quality by today's standards. Convert to MP3 or AAC for modern use. Historical importance in early internet audio streaming.
专业格式
DTS Coherent Acoustics - surround sound codec competing with Dolby Digital. Higher bitrates than AC-3 with potentially better quality. Used in DVD, Blu-ray, and cinema. Supports up to 7.1 channels and object-based audio. Perfect for high-quality home theater. Premium audio format for video distribution. Convert to AC-3 or AAC for broader compatibility.
Core Audio Format - Apple's container for audio data on iOS and macOS. Supports any audio codec and unlimited file sizes. Modern replacement for AIFF on Apple platforms. Perfect for iOS app development and professional Mac audio. No size limitations (unlike WAV). Can store multiple audio streams. Convert to M4A or MP3 for broader compatibility outside Apple ecosystem.
VOC (Creative Voice File) - audio format from Creative Labs Sound Blaster cards. Popular in DOS era (1989-1995) for games and multimedia. Supports multiple compression formats and blocks. Legacy PC audio format. Common in retro gaming. Convert to WAV or MP3 for modern use. Important for DOS game audio preservation.
Speex - open-source speech codec designed for VoIP and internet audio streaming. Variable bitrate from 2-44 kbps. Optimized for speech with low latency. Better than MP3 for voice at low bitrates. Being superseded by Opus. Perfect for voice chat, VoIP, and speech podcasts. Legacy format replaced by Opus in modern applications.
{format_dss_desc}
如何转换文件
上传您的文件，选择输出格式，立即下载转换后的文件。我们的转换器支持批量转换并保持高质量。
常见问题
什么是M4A，它与MP3有什么不同？
M4A (MPEG-4 Audio) is Apple's container format for AAC-encoded audio files. It's essentially AAC audio in a special wrapper optimized for iTunes and Apple devices. At the same bitrate, M4A (using AAC codec) sounds noticeably better than MP3 - roughly 20-30% more efficient. A 128kbps M4A sounds like a 160kbps MP3.
区别：M4A是一种现代格式（1990年代末），而MP3是旧格式（1993年）。M4A使用更先进的压缩技术，能够更好地保留音频。M4A还具有更好的元数据支持 - 艺术作品、歌词、章节等都比MP3的ID3标签工作得更好。这是iTunes用于所有音乐购买和刻录CD的格式。
我什么时候应该使用M4A而不是MP3？
在以下情况下选择M4A：
iTunes & Apple Devices
iPhone、iPad、iPod、Mac的原生格式。完美的iTunes集成。元数据、艺术作品，一切都能完美工作。
相同大小下更好的质量
M4A在相同比特率下的音质优于MP3。如果质量很重要且设备支持，M4A是更优的选择。
丰富的元数据需求
艺术作品、歌词、章节、评分在M4A中工作得更好。iTunes库管理在M4A文件中表现出色。
仅限现代设备
如果您所有的设备都是2010年后发布的智能手机/电脑，M4A在您需要的地方都能正常工作。没有旧版硬件。
Use MP3 for maximum compatibility (old devices, sharing with others). Use M4A for better quality, Apple ecosystem, and modern device usage.
M4A与AAC是一样的吗？
M4A和AAC是相关但不同的事物：
AAC是编解码器
AAC（高级音频编码）是减少文件大小的压缩算法。实际的音频编码方法。
M4A是容器
M4A是包含AAC音频和元数据的文件包装。可以把它想象成一个装有音频的盒子。
关系
M4A文件包含AAC编码的音频。当您“转换为M4A”时，您是在创建M4A容器中的AAC音频。
其他容器
AAC也可以放入MP4（视频）、3GP（移动）或ADTS（原始）。M4A专门用于仅音频文件。
扩展名含义
M4A = MPEG-4音频。它是MP4的音频专用版本。表示“此文件没有视频，仅有音频”。
实际使用
在实践中，人们将 M4A 和 AAC 互换使用。转换为 'M4A' 或 'AAC' 产生相同的结果。
文件扩展名
.m4a 扩展名用于音频，.mp4 用于视频。两者都可以包含 AAC 音频 - 扩展名澄清了内容类型。
请记住：AAC 是音频编码格式（压缩方式），M4A 是容器格式（打包方式）。M4A 文件使用 AAC 编码。
Can I play M4A files on Windows?
Yes! Windows has supported M4A since Windows Vista (2006). Windows Media Player, Movies & TV, and Groove Music all play M4A files natively. No additional software needed on Windows 7, 8, 10, or 11. Just double-click and they play like MP3 files.
Third-party options: VLC (plays everything), MusicBee (excellent music player), foobar2000 (audiophile choice), AIMP, iTunes for Windows. Pretty much every modern Windows audio player handles M4A perfectly. It's been standard for nearly 20 years.
Legacy Windows XP: Requires QuickTime or codec pack to play M4A. But if you're still on XP in 2025, audio format compatibility is the least of your problems! Modern Windows users have zero issues with M4A files - they work as smoothly as MP3.
为什么 iTunes 购买使用 M4A 格式？
Apple chose M4A because it's technically superior to MP3 and integrates perfectly with their ecosystem. Better audio quality at same file size means smaller downloads and less storage on devices. M4A's rich metadata support enables iTunes's library features - album artwork, ratings, play counts, smart playlists all work better with M4A than MP3.
Business reasons: M4A (AAC) was part of Apple's FairPlay DRM system for protected iTunes Store purchases. While iTunes now sells DRM-free music, they stuck with M4A because it became their standard. All their software is optimized for M4A, and billions of files already use the format.
User benefit: iTunes purchases at 256kbps M4A sound as good as 320kbps MP3 but are smaller files. The quality improvement is real - not just Apple marketing. For Apple users, M4A is the obvious choice. It's what the ecosystem was designed around.
M4A 和 M4P 之间有什么区别？
M4P is DRM-protected M4A! Both use AAC audio codec and MPEG-4 container, but M4P files have FairPlay DRM (Digital Rights Management) from Apple. M4P files only play on authorized devices/accounts - up to 5 computers, unlimited iOS devices signed into your Apple ID. M4A files have no protection and play anywhere.
History: Old iTunes Store purchases (pre-2009) were M4P. Apple switched to DRM-free M4A in 2009 under 'iTunes Plus' branding. Now all iTunes Store music is M4A (no DRM). M4P files still exist for Apple Music streaming (not owned, just access), audiobooks (M4B), and legacy purchases.
转换 M4P：您不能直接将 M4P 转换为 M4A，而不去除 DRM，这违反了 iTunes 服务条款。选项：使用 iTunes Match 升级到无 DRM 版本，刻录到 CD 然后重新提取（会损失一些质量），或购买无 DRM 版本。对于您拥有的内容，刻录到 CD 然后提取为 M4A/MP3 是合法的变通方法。
我应该使用什么比特率来处理 M4A 文件？
对于音乐：256kbps 是 iTunes 商店的标准，质量优秀 - 对于大多数听众来说是透明的。192kbps 适合移动设备，质量和大小平衡良好。128kbps 是可接受的最低值，适合随意听，但在高品质耳机上会有明显的压缩。320kbps 是过度的 - 256kbps 已经是透明的。
对于有声书/播客：64-96kbps 非常适合语音，非常高效。AAC 在低比特率下处理语音非常出色。128kbps 对于口语来说过于冗余。使用 AAC-HE（高效 AAC）在 48-64kbps 下可以获得更好的语音质量，同时文件大小极小。
比较：256kbps M4A ≈ 320kbps MP3 的质量。192kbps M4A ≈ 256kbps MP3。128kbps M4A ≈ 192kbps MP3。AAC 的高效性意味着您可以使用比 MP3 更低的比特率并获得相同的质量。这节省了存储和带宽，同时保持音频质量。
M4A 的技术规格是什么？
M4A 格式的主要特性：
音频编码
AAC（高级音频编码） - MPEG-4 第 3 部分。比 MP3 更高效，在相同比特率下质量更好。
容器格式
MPEG-4 第 14 部分（MP4 容器）。ISO 标准。存储音频、元数据、艺术作品、章节。
Metadata System
iTunes 风格的标签。艺术作品（JPEG/PNG）、歌词、评分、分组、广泛的字段。比 ID3 更好。
比特率范围
标准 AAC 的比特率范围为 8kbps 到 320kbps。AAC-LC 的比特率可高达 529kbps。支持可变和固定比特率。
采样率
支持 8kHz 到 96kHz。常见的有 44.1kHz（CD）或 48kHz（视频）。最多支持 48 个声道（环绕声）。
M4A combines modern AAC compression with flexible MP4 container. Result: better quality than MP3, richer features, Apple ecosystem integration.
M4A 可以包含无损音频吗？
Yes! M4A container can hold ALAC (Apple Lossless Audio Codec) - Apple's lossless compression format. These files still use .m4a extension but contain perfect-quality audio. ALAC in M4A gives you FLAC-quality audio (bit-perfect lossless) with iTunes/Apple device compatibility. File sizes are similar to FLAC - about 50% smaller than WAV.
混淆警告：大多数 M4A 文件包含有损 AAC 音频。一些 M4A 文件包含无损 ALAC 音频。它们使用相同的 .m4a 扩展名，但内部音频不同。检查文件属性或在 iTunes 中选择 '获取信息' 以查看内部使用的编码。ALAC M4A 文件比 AAC M4A 文件大得多。
When to use ALAC M4A: Ripping CDs for iTunes library in lossless quality, archiving music with perfect fidelity in Apple ecosystem, maintaining quality while using iTunes/Apple Music, needing lossless audio that syncs to iPhone (FLAC doesn't work on iOS). ALAC in M4A is Apple's answer to FLAC - same concept, Apple-compatible.
我应该在何时使用 M4A 与其他格式？
根据您的生态系统和需求选择 M4A：
M4A 用于 iTunes 库
非常适合 Mac 用户和 iTunes 组织。原生格式具有最佳特性。专辑封面、智能播放列表效果很好。
M4A 用于 iPhone/iPad
Native iOS format. Better battery life than MP3 decoding. Seamless Apple ecosystem integration.
M4A 用于质量
在相同比特率下比 MP3 更好的音质。如果设备支持 M4A，就没有理由使用 MP3。优越的音频编码。
MP3 用于兼容性
旧的 MP3 播放器、汽车音响、与他人共享。MP3 在任何地方都能工作。通用兼容性胜出。
FLAC 用于无损
Perfect quality archival. If not using Apple devices, FLAC better than ALAC M4A. More universal lossless format.
M4A 用于现代设备
智能手机、平板电脑、计算机（2010 年及以后）均支持 M4A。如果没有旧硬件，M4A 在技术上优于 MP3。
避免在旧设备上使用 M4A
旧的 MP3 播放器、复古汽车音响无法播放 M4A。如果支持 2000 年代的设备，请使用 MP3。
M4A 用于播客
在较低比特率下提供更好的语音质量。文件大小比 MP3 小。许多播客应用更喜欢 M4A。
M4A 用于 YouTube
YouTube 接受 M4A 上传。作为视频音轨的良好选择。AAC 是 YouTube 的原生音频编码。
M4A 作为默认格式
如果您仅使用现代设备，请将 M4A 设置为您的默认有损格式。在每个技术方面都优于 MP3。
为什么我的汽车音响无法播放 M4A 文件？
旧款汽车音响（2010 年之前）仅支持 MP3 和可能的 WMA。它们缺乏 AAC/M4A 解码芯片。尽管 M4A 是 iTunes 标准，但汽车音频制造商采用 M4A 的速度较慢。预算汽车音响仍然常常跳过 M4A 支持以降低成本。这令人沮丧，但这是汽车技术滞后的现实。
Modern cars (2012+) usually support M4A, especially if they have Apple CarPlay or Android Auto. Check your car stereo manual or test with one file. Some manufacturers list 'AAC' support but not 'M4A' - they're the same thing, just different names. If manual mentions AAC, your car should play M4A files.
变通方法：将 M4A 转换为 MP3 以便在汽车中使用。将 M4A 保留在手机/计算机上（质量更好），在汽车中使用 USB/CD 上的 MP3（兼容性）。随着存储成本的降低，同时维护两种格式并不繁重。或者使用蓝牙/CarPlay，从手机流式传输并完全绕过汽车音响的编解码器限制。
我可以将 MP3 转换为 M4A 以获得更好的质量吗？
不，转换 MP3 为 M4A 并不会提高质量！MP3 是有损的 - 在 MP3 编码过程中音频数据被永久删除。M4A 无法恢复丢失的内容。您是在从一种有损格式转码到另一种，这实际上会引入额外的压缩伪影。M4A 文件的声音会比原始 MP3 更糟。
将低分辨率的JPEG转换为PNG就像是格式改变，但质量并没有提高。将MP3转换为M4A的唯一原因是格式兼容性（设备需要M4A），但这会降低质量。尽可能从无损源（CD、WAV、FLAC）进行转换。
Correct workflow: Rip CDs or download music in lossless format (FLAC, WAV). Convert that lossless source to M4A for Apple devices AND MP3 for legacy devices. Keep lossless archives. This way you can generate any lossy format without quality degradation. Never go lossy to lossy - always start from lossless.
最佳的M4A编码器是什么？
Apple's own encoder (iTunes, Music app, afconvert on Mac) produces excellent M4A files optimized for Apple devices. It's the reference encoder and what iTunes Store uses. For Windows: iTunes works but is bloated. For command line: FFmpeg with libfdk_aac produces highest quality M4A files - often better than Apple's encoder.
FFmpeg with fdk-aac is considered the best AAC encoder by audio engineers. It produces slightly better quality than Apple's encoder at same bitrates. However, it's more complex to use (command line). For most users, iTunes/Music app is fine - quality difference is minimal and not worth the hassle.
Comparison: Fraunhofer FDK AAC (best quality, complex), Apple encoder (excellent, easy, native), FFmpeg's native AAC (good, sometimes worse than others), FAAC (older, lower quality, avoid). For casual use, iTunes does the job perfectly. For audiophiles or batch processing, FFmpeg with fdk-aac is worth learning.
我应该将我的MP3库转换为M4A吗？
一般来说不应该 - 将MP3转换为M4A会通过转码降低质量。如果您已经有MP3文件，请保持它们为MP3。仅从原始无损源（CD、FLAC、WAV）转换为M4A。将有损格式转码为有损格式总是会降低质量，即使新格式更“好” - 首次编码造成的损害是永久的。
例外情况：如果您有CD或无损音乐源，请重新抓取/转换为M4A而不是MP3。这将为您提供更好的质量，因为是新的编码。或者如果您需要M4A以兼容特定设备（如无法使用MP3的iPhone进行某些工作流程）。但绝不要仅仅为了格式原因将MP3转码为M4A。
Smart approach: Going forward, rip new CDs or downloads to M4A at 256kbps (if using Apple ecosystem) or FLAC (if platform-agnostic). Keep existing MP3 library as-is. Gradually replace with better sources when available. Never transcode lossy formats - only encode from lossless sources. Patience preserves quality.
M4A是我音乐的最佳格式吗？
For Apple ecosystem users: YES. M4A integrates perfectly with iTunes, iPhone, iPad, Mac. Better quality than MP3, smaller files, richer metadata, native support. iTunes library features work best with M4A. Apple Music and iTunes Store use M4A. It's the obvious choice for iOS/macOS users who don't need legacy device compatibility.
For mixed ecosystems: Maybe. M4A works on modern Android, Windows, Mac, iOS - basically everything from 2010+. If you have older devices (vintage MP3 players, old car stereos), MP3 is safer. If all your gear is modern, M4A's technical advantages make it the better choice. Quality per megabyte beats MP3 decisively.
Ultimate answer: For lossless archival, use FLAC (or ALAC M4A if Apple-only). For lossy listening copies: M4A if you're Apple-focused or have modern devices, MP3 if you need maximum compatibility. With storage cheap, maintain lossless archives and generate both M4A and MP3 from those. Best of both worlds - quality and compatibility.