Measure your real internet download speed with our free Internet Speed Simulator. Fetch a CDN binary payload, time the transfer, compute download Mbps, measure connection latency ping, and rate your throughput quality directly inside your browser.
Press the button to initiate CDN file download and latency ping probes.
Watch the animated gauge dial calculate real-time download Mbps.
Check download Mbps, connection ping, and throughput quality rating.
Fetches a known-size CDN JavaScript bundle and times bytes-per-second to compute accurate Mbps.
Clocks HTTP round-trip milliseconds to measure real connection latency before bandwidth testing.
All speed calculations execute in local browser memory. Zero bandwidth logs are stored on BunchTool servers.
Browser download speed tests use the Fetch API to retrieve a known-size binary payload from a CDN endpoint. Elapsed transfer time is measured with performance.now() at microsecond precision, computing: Mbps = (bytes × 8) / (ms / 1000) / 1,000,000.
Connection latency (ping) is measured by timing the round-trip HTTP no-cors request before the download probe. Values below 50ms indicate low-latency fiber or cable connections, while values above 200ms suggest mobile or high-hop routing.
Browser-measured speeds represent available bandwidth to the CDN endpoint and may differ from ISP advertised speeds due to TCP congestion window sizes, TLS handshake overhead, and local network bottlenecks.