在线把视频压缩到 5 MB

设定精确的 5 MB 上限，下载无水印 MP4。

当上传表单、聊天软件或存储规则要求文件不超过 5 MB 时使用此目标。压缩器默认设为 4.7 MB，为编码波动留出余量。

Where 5 MB comes from

Five megabytes usually comes from a form, ticketing system, learning portal or administrator rather than a consumer platform. It survives because it is cheap to store and quick to upload, not because one major service publishes it as a video cap.

No platform we track publishes 5 MB as a limit. Every cap in our verified set is listed on the platform pages, and none of them is 5 MB. If something is enforcing it on you, it is a local rule rather than a published one — which is worth knowing before you compress to it.

How long a video fits in 5 MB

The longest clip each resolution can carry inside 5 MB. “Comfortable” means the bitrate clears what that frame size wants; “watchable” means it is soft but holds together. Both columns are arithmetic on the size and the duration; the thresholds they are compared against are recommendations, documented under the table below.

Longest clip per resolution inside 5 MB
ResolutionComfortable up toWatchable up toNeeds
1080p9s19s4,000 kbps
720p17s33s2,200 kbps
480p36s65s1,000 kbps
360p56s96s600 kbps

Method: 5 MB spread over the duration, minus 128 kbps of audio and 2% container overhead, then compared against H.264 thresholds derived from published bitrate ladders and reduced by about a third for re-encoded source. A minute inside 5 MB leaves 557 kbps for video, which is exact. Which resolution that is enough for is a recommendation, not a measurement.

What 5 MB buys at each length

The table above reads by resolution; this one reads by duration. Same arithmetic, the other way round — pick your clip length and see what is left to spend.

视频时长留给画面的码率能撑住的分辨率结论
5s8,093 kbps1080p看着没问题
10s3,982 kbps720p看着没问题
15s2,612 kbps720p看着没问题
30s1,242 kbps480p看着没问题
1 min557 kbps480p能看
2 min215 kbps—明显糊

算法说明：码率这一列是纯算术——5 MB 摊到整段时长上，减去 128 kbps 的立体声音轨和 2% 的容器开销。这是硬上限，不是估算。分辨率和结论这两列是建议，依据是公开的 H.264 码率阶梯，并整体下调约三分之一——因为对已经压过一次的素材再编码，能承受的码率比编码原始母版更低。这里刻意保守：宁可说得难听点，也不想告诉你「没问题」结果画面糊掉。

5 MB 在不同时长和分辨率下的效果

左栏是每种时长可用于画面的码率，其他格子是各分辨率所需的码率。绿色表示余量充足，黄色表示能看但会偏软，灰色表示应该降低分辨率。沿着一列向下看，就能知道视频多长以后该分辨率不再适合 a 5 MB limit。

可用码率清晰画质所需码率1080p720p480p360p5 秒8,0934,0002,2001,00060010 秒3,9824,0002,2001,00060015 秒2,6124,0002,2001,00060030 秒1,2424,0002,2001,0006001 分钟5574,0002,2001,0006002 分钟2154,0002,2001,000600

来源： 计算结果，并非实测——生成此图时没有运行编码器 · 方法： 把 5 MB 分摊到整段时长，减去 128 kbps 音频和 2% 容器开销。阈值来自公开的 H.264 码率阶梯，并针对二次编码素材下调约三分之一。

What goes wrong at 5 MB

At 5 MB, duration is the whole decision. Keep a very short clip at 1080p, but drop longer footage to 720p or 480p before starving every frame. Trying to preserve 4K or a high frame rate inside this budget only spends bits on dimensions the codec cannot support.

如何把视频压缩到 5 MB

  1. 添加视频

    压缩器已设为 4.7 MB，让结果稳妥低于 5 MB 上限。

  2. 长视频先剪辑

    在 5 MB 内，时长比任何画质选项都更占预算。时长减半，每帧可用码率就翻倍。

  3. 下载并检查复杂画面

    全尺寸查看运动、人物面部和渐变；这些区域最先暴露压缩损伤。

5 MB 压缩常见问题

怎样把视频压缩到 5 MB？

上传视频，保留“目标大小”模式，并使用 4.7 MB 预设。输出是无水印 H.264 MP4。

为什么目标是 4.7 MB，而不是正好 5 MB？

目标大小编码可能有轻微波动。留出一点余量，可让下载文件稳定低于 5 MB 硬上限。

长视频也能压进 5 MB 吗？

可以，但时长越长，可用码率越低。请用本页表格判断何时降低分辨率会比强行保留原尺寸更清晰。

Other target sizes

Not one of these? Work out any size and length in the calculator — same arithmetic, plus what we measured at the bitrate it gives you.

Know the platform instead of the number?