How it reads a plate, and where it errs
Four steps, one of which is a guess. Knowing which one is the difference between a diary you can trust and a number you invented.
The four steps
- You photograph the meal. One frame, from wherever you happen to be sitting. No light box, no reference coin next to the plate.
- The photo goes off to be recognised. With your own key, straight from your device to the platform whose key you entered, without passing through our server (there are nine, named in the privacy policy). With the Snapfork key, through our server and onward through OpenRouter to the model provider; it is not stored here, and we do not hand the request to providers that retain what is sent. The route is your choice, and by default the app tries your key first and ours only after yours has failed; a checkbox in settings turns even that off. The page on data goes through it in full.
- The model names the dishes and estimates the weights. This is the step that is a guess, and the rest of this page is about it.
- You correct it, and the day adds up. Change a weight and the calories and macros recalculate — for the meal and for the day.
Where it gets things wrong
Recognising what is on the plate is the part models are good at. Estimating how much is on the plate is the part they are not, and no amount of better prompting fixes it, because the information is not in the photograph to begin with.
Depth is invisible
A bowl of soup and a shallow plate of soup look the same from above. So do a thin and a thick slice of the same cake.
Scale has no anchor
Plates come in sizes. Without something of a known size in the frame, a large portion on a large plate looks ordinary.
Fat hides
Oil in the pan, butter in the mash, cream in the sauce. Nothing in the picture says how much of it went in.
Which is why the weight is editable
Every estimate arrives as a number you can change, and changing it is the normal case rather than a correction of a failure. Weigh what you can, adjust what you cannot, and let the model save you the typing. A diary that is roughly right every day is worth more than one that was exact for a week.
What you need to run it
Nothing beyond signing in: two photos a day are recognised on the Snapfork key for free, and there is no invitation to wait for. Your own platform API key is optional — it removes the daily cap and the extra hops on the photo's way out, lives in your device's storage and is never sent to us. What the two Google key tiers mean for your photographs is on the questions page.