Slang AI, Loman, Novexia… : comparing AI voice agents for restaurants in France

A ringing phone in a full dining room is a lose-lose situation. Either a server drops a plate to answer, or the call goes unanswered and a booking walks to the restaurant next door. AI voice agents promise to solve exactly this: pick up every call, take the reservation, and let your team focus on the guests already in the room. Slang AI, Loman and Novexia are three of the names that come up most often for restaurants, but they are not interchangeable, and the right choice depends on your language mix, your existing setup, and what you want to do with the data afterwards.

This article is not a ranking and it is not a scorecard. It is a set of criteria you can use to evaluate any AI voice agent honestly, applied fairly to the market as it stands in 2026. We name Novexia where it is relevant, we build it, but the point is to help you ask the right questions, not to sell you a single answer.

What actually matters when comparing AI voice agents for restaurants?

Marketing pages tend to lead with voice quality and "24/7 answering", which most serious tools now handle well. The differences that actually change your daily operations are less glamorous: which languages the agent speaks natively, whether it plugs into the number your guests already know, where your reservation data ends up, and whether you can leave without losing everything. Treat those as your real shortlist criteria.

• Language coverage, genuinely native French and English, plus Dutch (NL) if you serve Belgium.
• Works on your existing number, no migration, no new line for guests to learn.
• A portal you own, reservations, call logs and contacts you can search and export (CSV / API).
• WhatsApp automation, for confirmations, reminders and two-way booking.
• Voice cloning, an optional custom voice that matches your brand.
• Multi-vertical fit, useful if you run more than a restaurant, or plan to grow into other services.

Does the agent handle French, English and Belgian Dutch properly?

This is where many US-born tools show their origin. Several of the best-known AI voice agents for restaurants, Slang AI and Loman among them, were designed first for the English-speaking market. That does not make them bad products; it means their sweet spot is an English-language dining room. For a bistro in Lyon or a brasserie in Brussels, the questions are more specific: does the agent understand a caller who slides between French and English mid-sentence? Does it pronounce your dishes and your street name credibly? And in Belgium, can it also take a reservation in Dutch? An agent that is merely translated is not the same as one that is natively bilingual.

Novexia was built for France and Belgium first, with native French and English and Dutch (NL) support for the Belgian market. If your callers are mostly French-speaking with international guests in the mix, native language handling is not a nice-to-have, it is the difference between a smooth booking and a frustrated hang-up.

Will it work on your existing phone number, or force a migration?

Your phone number is on your door, your Google listing, your napkins and thousands of receipts. Any solution that asks guests to call a new number quietly hands you a marketing problem. The better approach is call forwarding: your existing line rings, and when no one picks up, or after hours, the AI answers on the same number. Most credible tools support this, but confirm it explicitly, and check whether forwarding is conditional (only when you are busy) or full-time. This is a criterion where the leading options, Novexia included, tend to align: keep the number your guests already know.

Where does your reservation data live, and can you get it back?

Every call an AI agent handles produces something valuable: a guest name, a phone number, a party size, a date, sometimes an allergy or a preference. Over a year that is a real customer database. The question that separates tools is whether that database is yours. Look for a back-office portal where you can search past calls and bookings, and, critically, export everything to CSV or pull it through an API. If a tool keeps your data in a black box you cannot export, you are renting your own customer list. Under the GDPR you also have the right to access and delete personal data, so a genuine export path is not just convenient, it supports your compliance obligations.

Does it go beyond voice, WhatsApp, reminders and voice cloning?

Answering the phone is the baseline. The tools worth a closer look add channels around it. WhatsApp automation lets the agent send a booking confirmation, a reminder the day before, or handle a two-way exchange when a guest wants to move a table, which quietly reduces no-shows without staff time. Voice cloning is a smaller but real differentiator: an optional custom voice so the agent sounds like an extension of your brand rather than a generic assistant. Not every restaurant needs these, but if you already run a busy WhatsApp line or care about brand consistency, they change the calculation. Novexia offers WhatsApp automation and optional voice cloning alongside the voice agent; other tools vary, so check feature by feature rather than assuming parity.

Restaurant-only or multi-vertical, which fits your business?

Some agents are purpose-built for restaurants and nothing else. That focus can be a strength: deep handling of table management, waitlists and menu questions out of the box. Loman and Slang AI, for example, position squarely around the dining room. Others, Novexia included, are multi-vertical, the same engine also serves clinics, salons and trades. If you only run a single restaurant, specialisation may feel more tailored. If you run a group with a bar, a private-events space, or ambitions beyond food, a platform that generalises can consolidate everything under one system. Neither is objectively better; it depends on where your business is heading.

The best AI voice agent is not the one with the best demo. It is the one that speaks your guests' languages, answers on the number they already dial, and leaves the data in your hands.

How should you run your own comparison before deciding?

Pricing and headline features change often, so do not rely on a static table you found online, including this one. Instead, book a demo with each shortlisted provider and run the same test: call in French, then switch to English mid-conversation, then (if relevant) try Dutch. Ask to see the back-office portal live and request a sample CSV export. Confirm forwarding works on your current number, and ask, plainly, what happens to your data if you cancel. A vendor comfortable answering those questions is usually a vendor worth trusting.

For Novexia specifically, a demo is a 20-minute Calendly call rather than a public phone number, we would rather walk you through your exact scenario than have you judge us on a canned recording. Whatever you choose, use the six criteria above as your checklist, and let your actual call mix, not the marketing, decide.