On this knowledge base, the marketplace with a native French interface is WeTheNorth (WTN). The interface is fully bilingual English/French, including vendor messages and dispute pages — not a thin translation layer.
Canadian focus
WTN’s audience focus is Canadian. Shipping defaults to Canada-only and most vendors ship domestically. The name is a Toronto Raptors slogan. For a French-speaking Canadian buyer the language and shipping defaults make WTN the practical choice.
How the bilingualism is implemented
WTN switches the interface language based on an account preference. Both languages are first-class — the French isn't machine-translated and isn't fallback-to-English. Vendor messages also carry parallel French copy where vendors have written them that way, which is most of them given the Canadian buyer base. Moderation is bilingual: dispute reviews accept evidence in either language.
Why no other markets are bilingual
Most Tor markets are English-only because that's the default vendor and buyer language on the network. WTN's Canadian focus made French support cost-effective — there's an actual French-speaking buyer population to serve. Other markets would have to translate their entire interface to capture a much smaller addressable audience, and the math doesn't currently work.
See also
Why the interface language is not a cosmetic detail
Listing descriptions are where expectation gaps are born, and an expectation gap is where a dispute comes from. A description you half understand is an argument waiting to happen about what was promised. Reading listings in the language you are strongest in is one of the cheapest things you can do to avoid ending up in arbitration over a misreading.
Translated interface versus translated content
A market can translate its own menus and still leave every vendor listing in English, which is the common case and much less useful than it sounds. The thing worth checking on arrival is whether the listings themselves are bilingual or only the furniture around them.
What a national focus changes in practice
A market built around one country tends to mean domestic transit rather than customs, which is where most delivery uncertainty comes from. Shorter and more predictable windows follow from that, and so do fewer disputes about timing. If you are outside that country the advantage disappears entirely and a global market suits you better.