返回播放器

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最后更新：2026 年 10 月 25 日

「在线 MIDI 播放器」是一个免费、无需安装的网页工具，用来在浏览器里直接播放 MIDI 文件，并把音符画成可以跟随的可视化画面。

为什么做这个站

很多人手里存着一批 .mid 文件，却经常遇到两种麻烦：要么找不到能正常播放的软件，要么为了听一遍就装上几个 GB 的乐器音源。而练琴时又有一个额外的问题——光听声音不够，你需要看见音符什么时候落下、哪些键需要一起按。

这个站想把这两件事一起解决：打开网页就是播放器，加载文件就能听，声音和画面同时给出。

它是怎么工作的

整个播放器是一个纯前端的单页应用，没有后端服务，所有处理都在你的浏览器里完成：

• 音频：使用 Web Audio API 实时合成。音色取自 FluidR3 网络音源，可在控制栏切换大钢琴、电钢琴、八音盒等八种音色；加载失败时自动降级为内置的合成钢琴音色，保证仍然能出声。
• 解析：MIDI 文件在本地用 JavaScript 解析，提取每个音符的音高、起止时间与力度，并按文件内的 Tempo 事件还原速度变化。
• 绘制：音符滚动区与钢琴键盘都画在 Canvas 上，按帧刷新，并在窗口尺寸变化时重新计算坐标，避免高清屏上出现模糊或错位。

因为全部在本地完成，所以文件不需要上传，也没有排队等待的环节。文件越大，解析时间越长，但依然只消耗你自己的设备性能。

「十指可弹」检测的由来

站内的合规检测逻辑，最初是为了把从音频转录出来的钢琴 MIDI 上传到 AI 演奏平台。这类平台通常要求同时发声的音符不超过十个、不允许出现零长度音符、音域控制在八十八键之内。

把检测做进播放器之后，你在听的同时就能看到这些数值，不必再另外跑一遍独立工具。对于想确认一份谱子是否适合真人演奏的人，这些指标同样有用。

隐私

本站不收集你的文件，不要求注册，也不会把曲目内容发送到服务器。详细说明见 隐私政策。

Back to the player

About this site

Last updated: October 25, 2026

Online MIDI Player is a free, install-free web tool for playing MIDI files directly in your browser and drawing the notes as a visual you can follow.

Why it exists

Many people keep a folder of .mid files but run into the same two problems: either they cannot find software that plays them properly, or they have to install gigabytes of instrument samples just to listen once. Practising adds another issue — listening alone is not enough, because you need to see when the notes fall and which keys must be pressed together.

This site tries to solve both at once: open the page and the player is there, load a file and it plays, with sound and picture delivered together.

How it works

The whole player is a pure front-end single-page application with no back-end. Everything happens in your own browser:

• Audio: synthesised in real time with the Web Audio API. The timbre comes from the FluidR3 web sound source, and you can switch between eight voices (grand piano, electric piano, music box and more) from the control bar; if it fails to load, playback automatically falls back to a built-in synthetic piano voice so you still hear sound.
• Parsing: the MIDI file is parsed locally in JavaScript, extracting each note's pitch, start and end time and velocity, and restoring tempo changes from the file's tempo events.
• Rendering: the note roll and the piano keyboard are both drawn on Canvas, refreshed per frame, and recomputed on resize so nothing blurs or misaligns on high-density screens.

Because everything is local, files are never uploaded and there is no queue to wait in. Larger files take longer to parse, but they only consume your own device's performance.

Where the ten-finger check came from

The compliance logic on this site started as a way to prepare piano MIDI transcribed from audio for upload to AI performance platforms. Those platforms typically require no more than ten simultaneous notes, no zero-length notes, and a range within the eighty-eight keys.

Once the check was built into the player, those numbers became visible while listening, so there was no need to run a separate tool. The same metrics are useful for anyone checking whether a score is realistic for a human performer.

Privacy

This site does not collect your files, does not require registration, and never sends track contents to a server. See the Privacy Policy for details.