标签：#dataloss

I had a long Google AI Studio (Gemini) session that I wanted to keep. I selected the conversation in the browser, copied it, and pasted it into a text file. File size: a few hundred KB. "OK, that's safe." Later, I exported the same session as JSON. File size: a few MB. More than half of the data had silently disappeared. What was missing I checked what the manual copy had dropped. The system prompt The instruction I had originally given the model — the system prompt — was completely gone. Manual copy captures only the user/assistant turns visible in the conversation pane. The instruction context that shaped the entire session does not get copied. The tail of long responses When a Gemini response is long, the browser shows a "Show more" button. If you copy without expanding it, the response gets cut mid-sentence. Out of 8 sessions I checked, 3 had responses truncated this way. Newlines inside code blocks Newlines inside code blocks got mangled in several places. Responses containing JSON or YAML had indentation that no longer parsed. The reasoning trace For some models, the model's reasoning trace is stored separately from the visible response. Manual copy doesn't capture it at all. How to export as JSON Google AI Studio has a session export feature. In the session view, click the ... menu at the top right Select "Export" Choose JSON format and download The JSON contains the full data, including the system prompt. Measured: manual copy vs. JSON export I compared 8 sessions. Session Manual copy JSON Loss rate A tens of KB ~150 KB ~70% B ~90 KB ~200 KB 50-60% C ~30 KB ~100 KB 60-70% D ~50 KB ~180 KB ~70% E ~60 KB ~240 KB ~70% F ~20 KB ~70 KB ~60% G ~20 KB ~50 KB 50-60% H ~10 KB ~30 KB ~60% Total a few hundred KB ~1 MB 60-70% Average loss rate, 60-70%. The manual copy was, on every session, missing most of what was in the actual session state. Why I didn't notice If you open the manually-copied file, the conversation reads fine. As long as the start and end connect, a m