Why I Built a Speed Test From Scratch

The Problem With Existing Speed Tests

Most internet speed test sites are terrible. They are bloated with ads that compete for bandwidth during the test itself, skewing results. Some use HTTP-based measurement that adds request overhead to every data chunk, inflating latency and underreporting throughput. Others are funded by ISPs and have been caught reporting optimistic numbers. I wanted a speed test that was accurate, fast, and did not make me close three pop-ups before I could click "start."

Why WebSockets Matter for Accuracy

The biggest design decision was using WebSockets instead of HTTP requests. Most speed tests work by downloading and uploading files via HTTP, but every HTTP request carries overhead: headers, connection negotiation, and TCP slow-start. That overhead gets baked into the measurement. A WebSocket connection is opened once and stays open, letting data flow continuously in both directions. This means the measurement reflects actual sustained throughput, not throughput plus protocol tax.

For latency, the persistent connection is even more important. Bolt Bunny sends a series of small ping messages and measures the round-trip time for each. Because there is no connection setup per ping, the measurement captures true network latency rather than latency plus handshake time. Jitter is calculated as the variation across those samples.

Adapting to the Connection

A naive speed test sends a fixed amount of data and divides by time. That approach falls apart on both very slow and very fast connections. Bolt Bunny ramps up gradually, starting with small data chunks and increasing the size as it gauges the connection. This warm-up phase avoids TCP slow-start distortion. The final speed is calculated over a stable window of sustained transfer, ignoring the ramp-up period entirely. The result is a number that reflects what your connection actually delivers under load, not a best-case burst.

What the Results Tell You

After a test completes in about 15 seconds, Bolt Bunny shows download and upload speeds in Mbps, ping in milliseconds, and jitter. More importantly, it contextualizes those numbers: whether your connection can handle 4K streaming, video calls, online gaming, or large file transfers. A results history tracks your connection performance over time, which is useful for catching ISP throttling patterns or verifying that an upgrade actually improved things.

No account needed. No data stored on our end. Open the page, run the test, get honest numbers.