Glossary
What is a no-log AI?
A no-log AI is one that keeps no record of your prompts or its answers once the request is complete — the term is borrowed from the VPN industry, and it carries the same problem: anyone can say it, and almost nobody defines which logs they mean.
The three things people call "logs"
Content logs — the prompt and the response. This is what the phrase should mean, and it is the only one that matters for whether a conversation can be read back to you.
Metadata logs — that a request happened, when, from which key, how large it was. Billing and abuse prevention need some of this, so a service claiming absolutely none of it is usually claiming something it does not do.
Infrastructure logs — load balancers, error traces, crash dumps. These leak content accidentally rather than by design, which is why the honest version of the claim is narrower than the marketing version.
How to check it rather than believe it
Look for the boundary, not the adjective. A service that says "no content logs; request counts retained for billing" is telling you more than one that says "no logs" and stops.
Ask what the upstream provider does. A front end cannot promise more than its supplier agreed to, and this is where most no-log claims quietly fail.
Run the cheap test yourself: close the tab, come back, and see whether the conversation is still there. On nokeep it is gone, because there is no account for it to have been filed under.
Asked before you asked
Is "no-log" the same as "zero data retention"?
Nearly. Zero data retention is the contractual term used between a service and its model provider; no-log is the consumer-facing phrase. Zero retention is the more precise one, because it names what it covers.
Can a no-log service still be compelled to hand something over?
It can be compelled to hand over whatever it holds. If it genuinely holds no content, there is nothing responsive to produce — which is a different position from having it and being asked.
Does no-log mean anonymous?
No. A service can keep no content logs and still know exactly who you are through your account and payment method. No-account and no-log are separate properties, and you want both.