延迟与吞吐量
延迟影响响应速度，吞吐量影响大量数据的传输速度。视频通话既需要足够带宽，也需要稳定延迟。
Internet speed test
Measure download, upload, ping and jitter directly in your browser.
Indicative HTTP test via Vercel: server processing may affect ping and upload.
—↓ Download Mbps
—↑ Upload · Mbps
—↕ Ping · ms
—≈ Jitter · ms
How this internet speed test works
The test first sends tiny requests for ping and jitter, then transfers several blocks in parallel to estimate download and upload. Values update while the test is running.
Download
Download speed determines how fast your device receives data. It affects streaming, downloads and page loads.
Upload
Upload speed matters for video calls, live streaming, cloud backups and file sharing.
Ping / Jitter
Ping measures round-trip latency to the server. Jitter measures how much that latency varies. Competitive gaming and calls benefit from low, stable values.