Is Brarista a ChatGPT Wrapper? How AI Bra Fitting Actually Works

The moment we describe ourselves as an AI chatbot, a reasonable question follows: isn't this just ChatGPT dressed up for lingerie? If you work in this industry, you'll know how badly generic AI performs on bra fit. It confidently converts a 32E in one brand to the same size in another, and can't begin to tell you whether that bra will actually suit your breast shape. The lingerie industry has every reason to be sceptical.

But that scepticism is also exactly why Brarista exists. Six years of R&D, a founding team of professional bra fitters, and no single existing solution to the real pain points of this industry. Below, our engineering team and bra fitting experts explain exactly how and why it matters.

At a glance:

Built from the fitting room

We've been in development since 2020, founded by a professional bra fitter and shaped by ongoing conversations with fitters and lingerie retailers from the start. We also have a strong co-creation culture, bringing in real shoppers at least once a month to test and feedback on the product. The team iterates accordingly, until the experience works for bra wearers across every size range and market.

That grounding matters. Because the instincts of a trained fitter, knowing when a size chart is misleading, when a style won't work for a particular shape, when a customer needs a sister size rather than their usual one, are not things you can scrape from the internet. They have to be built in deliberately.

What’s actually under the hood

Here is the most common misconception about AI tools: that they calculate. They don't. A tool like ChatGPT receives a question and predicts a plausible-sounding answer. It is doing pattern-matching, which is why it confidently produces sizes that don't exist.

Brarista works differently. The AI's job is narrow: understand what the customer is asking and keep the conversation natural. The moment any size logic is needed, whether that is a conversion, a measurement, or a regional difference, the system hands off to our separate rules engine built specifically for each brand. The AI cannot override those rules, and it cannot generate a size on its own. Sizing is 100% deterministic. Brarista cannot recommend a size that isn't in your size chart.

Every output is also validated before it reaches the customer, so there is no path for a wrong recommendation to make it into the conversation.

Universal size mapping

Sitting underneath all of this is Brarista's universal size conversion system: a comprehensive, multi-country size-mapping chart covering every client and the various brands in the market.

When a customer says "I'm a 34A in M&S, what am I in your brand?", a generic AI guesses. Brarista matches against your actual size chart and fit logic, even if your sizing system is entirely bespoke. We've built this for brands like Evenly and Marbra, each with its own conventions, each handled precisely.

"We're confident we're the only platform in the business that does this inside a chatbot."
- Bella Trang Ngo, Founder of Brarista

Sister sizing

Sister sizing is something every trained fitter knows instinctively: the ability to offer a customer a viable alternative when their exact size isn't available, without just telling them to look elsewhere. It is also something generic AI tools cannot do meaningfully, because they have no awareness of your stock, your size range, or your brand's specific conversion logic.

When a customer's exact size is out of stock or outside a brand's range, Brarista’s sister sizing tool automatically surfaces the best sister size alternative for that specific brand. Customers always have a viable next step. The sale doesn't have to be lost.

The fitting quizzes

The conversational experience can also shift into something more visual and guided whenever it helps. Brarista's fitting quizzes are built directly into the chat flow, as well as available as a standalone sidebar, so customers can move between conversation and a more structured format without ever leaving the experience.

Brarista includes a suite of fitting quizzes, each targeting a specific customer need:

• Help me find my bra size

• Help me find the best style for my shape

• My band feels too tight

• My cups feel too tight

• My bra is giving me red marks

• I'm getting shoulder pain

The core size-finding quiz helps customers find their correct size in under two minutes, using the same benchmarking method a trained fitter uses in a boutique: comparing fit by eye against a bra the customer is already wearing.

"Just what you do in a store. The best fit tool I have seen."
- Maria, co-creator of Brarista and Sales Director at Pour Moi

But size is normally just the starting point. The breast shape quiz goes further, assessing a wider range of body features including breast spacing, side and top fullness, bottom gap, shoulder slope, and life stage, to pinpoint which products will actually suit a customer's body rather than just their measurements. It is the difference between knowing someone is a 34D and knowing which 34D will work for them.

The remaining quizzes are built for what happens after the purchase. When a customer has a fit issue, the instinct is to return. These quizzes are designed to change that: by helping customers diagnose the problem, they open the door to an exchange instead, protecting revenue and reducing the return rates that quietly eat into lingerie margins.

Onboarding, and what happens after

Getting set up takes as little as one week. We take in your product catalogue and customisation requirements to tailor the experience to your brand, and we are on hand throughout. But the work doesn't stop at launch, and neither does the accuracy.

After go-live, we monitor customer conversation logs and feedback continuously, feeding relevant insights back into the system with particular attention to products that sit outside standard sizing expectations. The longer Brarista runs on your site, the better it knows your catalogue.

When issues arise, our QA team follows a structured process: reproduce the problem, identify the root cause across the relevant component, whether that's the knowledge base, size mapping, product database, or front-end behaviour, and resolve it with full testing before closing it out. Data issues are updated and verified internally. Anything code-level goes to engineering with full context and is retested before we sign it off.

We aim to resolve most issues within a day. When something takes longer, we keep clients informed with clear timelines and updates throughout, not just a resolution note at the end.

"My approach focuses on thorough investigation, clear ownership, and proactive communication, so that issues are resolved efficiently and clients feel supported throughout."
- Zeynep, QA Manager at Brarista

Why this matters

A customer doesn't arrive on your site ready to buy. They arrive with questions. Does this come in my size? Will this work under my dress? I'm usually a 34E but I don't trust that here. The gap between that first question and a completed purchase is where most lingerie retailers quietly lose revenue, not to competitors, but to uncertainty.

Brarista sits in that gap. By the time a customer has engaged with the chatbot, they have already discovered your brand, explored your catalogue, and started building a relationship with it. Brarista's job is to make sure that momentum doesn't stall at the sizing question. It answers like your best sales assistant would: with genuine fit knowledge, specific product recommendations, and the kind of confidence that turns consideration into a sale.

Here is what that journey looks like in practice, and where Brarista makes the difference:

Every touchpoint in that journey can be tailored to your brand. Your sizing system, your catalogue, your tone, your aesthetic. The experience a customer has with Brarista on your site is not a generic chatbot with your logo on it. It is a fitting assistant that knows your products, speaks in your voice, and reflects the standard of service your brand stands for.

That has a direct effect on your acquisition costs too. When customers convert at a higher rate, the spend it took to bring them to your site works harder. Every session that ends in a purchase rather than an abandoned basket improves the return on every marketing pound you have already spent.

The numbers from our early implementations reflect that. Across Barista-assisted sessions, we have seen a 37% increase in add-to-cart rate, a 34% higher average order value, and customers who use the chatbot are 85% less likely to return their purchase compared to those who don't.

That is the difference between a generic AI tool and a fitting tool built specifically for this industry. If your current chatbot can't do this, it's time to see what Brarista can. We're always happy to show you the product in your own catalogue first. Book a demo at bella@brarista.fit.