What’s in an upload

When you save a capture, YANL writes a plain, human-readable text log: one line per moment in time, so nothing is hidden and you can open it yourself.

What a log contains

A capture is a simple sequence:

• It opens with your device and session details.
• It then records one reading per second: every metric for that moment.
• Events (things like a cell change, a handover, or losing service) are written as they happen.
• If the phone ever pauses the app and a second is missed, the log marks that gap honestly rather than papering over it.
• It closes when you stop recording.

Because every second is written (not just the moments something changes), the timeline is complete and evenly spaced, which is what lets the web viewer replay it smoothly.

Missing readings

If the hardware didn’t report a value (Wi‑Fi off, aeroplane mode, or a reading the radio simply didn’t provide), the log records it as empty, never as a made-up zero. So a blank in the data always means “no reading here”, not “zero”.

Some readings are little tables rather than single numbers, such as the connected Wi‑Fi details or an iPerf result; these are stored as small labelled rows.

If an upload fails

If an upload ever fails as “corrupted or invalid”, re-capture on a current app build, and include the Reference shown on screen when you contact team@yanl.net.

See also

• Data quality & real-world behaviour: freshness and aeroplane mode
• Metrics reference: every reading, with units
• Troubleshooting: upload errors