Compare · AI carb counting
Counting carbs from a photo: ChatGPT, Gemini, Cal AI and diabetes apps compared
Glide, ChatGPT, Gemini, Claude, Cal AI, SNAQ and Gluroo. Checked against each maker's own documents on 21 October 2026.
Many people with type 1 diabetes already photograph a plate and ask ChatGPT for the carbs. This page puts the chatbots next to the apps built to count carbs from a photo, on what happens after the number: is it logged, does it sit next to the glucose, does the family see it. Glide's maker wrote this page, so read it as one vendor's comparison. Each claim links its source: the maker's help pages, terms, privacy policy or App Store listing, or a published study. Where those say nothing, the cell says not stated, which does not mean the app cannot do it. If a cell is wrong or out of date, write to [email protected] and we fix it.
The short version
- ChatGPT, Gemini and Claude give a carb number for any photo, free. The number stays in the chat: no meal log, no glucose next to it, no dose.
- Cal AI counts carbs from a photo or a barcode, for calorie and weight goals. Its documents mention no diabetes, CGM or insulin feature.
- SNAQ and Gluroo are built for diabetes: they read the CGM and log insulin beside the meal. Gluroo is free and shares everything with the family; SNAQ has published accuracy studies (Baumgartner et al., a randomized trial).
- Glide puts the estimate in an editable field, logs it with the dose on the glucose chart that every follower sees, and lines up each repeat of a meal in My Lab. It runs on iPhone and Apple Watch only, and photo carbs are Premium.
- None of them is for dosing unchecked. SNAQ and Gluroo say so in their terms; the chatbots say not to rely on them for medical advice.
Side by side
| Feature | Glide | ChatGPT | Gemini | Claude | Cal AI | SNAQ | Gluroo |
|---|---|---|---|---|---|---|---|
| Carbs from a meal photo | Built in (Premium): AI drafts the carbs and a description in an editable field, and nothing is logged until you accept it source | You attach the photo and ask. A general chatbot, no nutrition feature source | You attach the photo and ask. A general chatbot, no nutrition feature source | You attach the photo and ask. A general chatbot, no nutrition feature source | Built in: calories, protein, carbs and fat from a photo. Scan results need a subscription source source | Built in, the core feature; portion size from the depth sensor on iPhone Pro models source | Built in: a photo estimates carbs, calories, sugar and more source |
| Correct the estimate | Edit the number, or say it in plain words: “add an apple”, “only half the rice” source | You type it into the chat. Nothing specific to carbs | You type it into the chat. Nothing specific to carbs | You type it into the chat. Nothing specific to carbs | not stated | Adjust ingredients, swap portion sizes, or override the carb total source | Not stated for the AI estimate; a logged entry can be edited source |
| Barcode or nutrition label | Barcode scan for packaged food (Premium) source | Not stated; a photo of the label goes in like any other photo | Not stated; a photo of the label goes in like any other photo | Not stated; a photo of the label goes in like any other photo | Barcode scan source | Barcode and nutrition label scan source | Not stated; its barcode scan is for CGM sensors source |
| Built for | Type 1 diabetes: the person with T1D and the family who follows them source | General chatbot source | General chatbot source | General chatbot source | Calorie tracking, weight loss and muscle gain. Diabetes is not mentioned source | Diabetes (type 1, type 2, prediabetes, gestational) source | Type 1 diabetes source |
| Keeps a meal log | Yes: each meal with its photo, carbs and dose. My Lab lines up the repeats of a meal (Premium) source | Chat history only; a meal log is not stated | Chat history only; a meal log is not stated | Chat history only; a meal log is not stated | Food diary with PDF export source | Food log with reports source | Searchable event log with CSV export source source |
| Meal next to CGM glucose | Yes: Dexcom, Libre and Medtrum readings, with each meal and dose on the chart source source source | not stated | not stated | Not stated; its Apple Health connection (beta, US) does not list blood glucose source | Not stated; Apple Health is for steps source | Yes: Dexcom, Libre, Eversense, Apple Health, Nightscout, Glooko source | Yes: Dexcom Share, LibreLinkUp, several pumps source |
| Log insulin doses | Yes, from any family phone; Tandem and Glooko pump doses import source | not stated | not stated | not stated | not stated | Yes, beside the meal; doses also import from Dexcom, Glooko and Nightscout source source | Yes: injections, smart pens, Loop, iAPS source |
| Family sees the meal | Yes: every follower on the profile sees the meal, the carbs and the dose source | A read-only link to one chat | A public link to one chat | A snapshot link to one chat, without the attached photo | Not stated; a family plan exists source | Not stated; reports for the care team source | Yes: everyone in the GluCrew sees the log and the alerts source |
| Published carb accuracy | Our own tests, by test set: the average miss and the misses of more than half the meal source | GPT-5: 8.7 g average miss on 150 photographed foods averaging 35.2 g source | Gemini 1.5 Pro: 66% average error on 52 meal photos source | Claude 3.5 Sonnet: 73% average error on 52 meal photos, mostly from one misread photo source | No carb figure. Cal AI says it is “about 80% accurate”; an NIH abstract found four photo apps, Cal AI among them, under-counted calories source source | 13.1 g average miss on 26 meals at 3 portion sizes, against 21 g for people with T1D counting by hand (difference not significant) source | not stated |
| Your photos train AI | No: photos go only when you tap, to a provider that keeps no copy and does not train on them source | Can be turned off: “Improve the model for everyone” in Data controls source | With Keep Activity on, chats and photos help train Google's AI and human reviewers read some of them source | Can be turned off: “Help improve Claude” in the privacy settings source | Its terms allow your content to be used to train AI models; an opt-out is not stated source | Its privacy policy lists machine learning and research; an opt-out is not stated source | not stated source |
| Price (US) | Free. Photo carbs are Premium: $7.99 a month or $59.99 a year for the whole profile source | Free; Go and Plus are paid plans source | Free; AI Plus, AI Pro and AI Ultra are paid plans source | Free; Pro $20 a month source | Subscription for scan results, after a 3-day trial source | Free with limited photo logging; Premium $7.99 a month source source | Free source |
| Phones and other screens | iPhone and Apple Watch source | iPhone, iPad, Android, web source | iPhone, Android, web source | iPhone, Android, web source | iPhone, Apple Watch, Android source | iPhone, Android source | iPhone, Apple Watch, Android, Wear OS, web source |
| What the maker says about dosing | Not a medical device: you review every estimate, and your number wins source | Its usage policies rule out medical advice without a licensed professional source | “Don't rely on Gemini Apps for diagnosis, treatment, medical advice” source | “We are not a medical device and cannot provide medical guidance” source | “We do not offer medical advice” source | Not to be used “to calculate insulin doses or determine bolus amounts” source | “Not intended for calculating insulin or other drug doses” source |
Studies of the chatbots tested specific model versions, often older than the ones the apps run today, and each used its own photos, so the numbers do not compare across columns. For a test of current models on one set of photos, see how Glide picks its model. Follower apps (Dexcom Follow, LibreLinkUp, Sugarmate and others) are compared on /compare.
Questions
Can ChatGPT count carbs from a photo?
It gives a number for any food photo you attach. In a published test, GPT-5 missed by 8.7 g on average on 150 photographed foods that averaged 35.2 g (Lian et al. 2026). On 240 food photos, GPT-4o was within 10 g for 93% of fruit and vegetables but for 47% of mixed meals (Johansen et al. 2026). The number stays in the chat: ChatGPT does not log it, put it on your glucose chart or record the dose.
Is Gemini or Claude better than ChatGPT for carbs?
One study gave the same 52 meal photos to several chatbots: Gemini 1.5 Pro missed the carbs by 66% on average and Claude 3.5 Sonnet by 73%, most of that from one photo it misread (Fridolfsson et al. 2025). Newer models have come out since. Glide re-tests each new model on the same photos and publishes the results on /science.
Is Cal AI good for type 1 diabetes?
Cal AI is built for calorie tracking and weight goals. Its listing does not mention diabetes, and its documents name no CGM connection or insulin log (App Store, FAQ). No published study gives its carb error; an NIH conference abstract found four photo apps, Cal AI among them, under-counted calories by 250 to 345 kcal a meal (NUTRITION 2026).
How accurate is counting carbs by hand?
Adults with type 1 diabetes missed by 15.4 g on average on meals that averaged 72 g, in a study of 448 meals (Brazeau et al.). A photo estimate is a second opinion, not a replacement: every app here says not to dose from it unchecked.
Which apps put the meal next to CGM glucose?
Of the apps here, Glide, SNAQ and Gluroo read CGM data and log insulin beside the meal (Glide, SNAQ, Gluroo). The chatbots and Cal AI document no CGM connection.
Glide is not affiliated with or endorsed by OpenAI, Google, Anthropic, Cal AI, SNAQ or Gluroo. Product names belong to their owners. Not a medical device; not medical advice.