A bilingual Dutch-French website in Belgium: how to do it

A good bilingual website runs on one domain, with a separate URL for each language: yourcompany.be for Dutch, yourcompany.be/fr/ for French. The language switcher shows the name of each language, not a flag, and never sends anyone to a language automatically. By all means let AI do the first translation, but have it reviewed by someone who knows the language well. This article has two parts: what you decide, and what you ask your web developer.

Why add a second language?

In Brussels, 81% of residents know French, 47% English and 22% Dutch, according to the VUB's language barometer (VUB, BRUZZ on VRT NWS). So a Brussels website in Dutch only is readable by only about one resident in five. And people who buy online want information in their own language: 76% of online shoppers prefer to buy products with information in their native language, according to a CSA Research survey of 8,709 consumers in 29 countries (CSA Research). For business-to-business services we found no public figure.

Part 1: what you decide

Are you required to be bilingual?

No, not as an ordinary business. Under the Belgian Constitution, the use of languages is free; the law can only regulate it for acts of public authorities and for court proceedings (Constitution, art. 30). The language laws also cover education, relations with your staff and certain mandatory company documents; a shopkeeper and their customer are in principle free to choose their language (Flemish government, in Dutch). A second language on your site is therefore a choice. Except on one point: you give your cookie information in the language of your audience (see below).

Which languages, and which one at your main URL?

Choose your customers' languages. For most small businesses in Brussels that means French and Dutch. If you work for expats or international companies, add English. Each language does mean extra work: translating, reviewing and keeping it up to date.

At your main URL (yourcompany.be), put the language of most of your customers, and the other language in its own subfolder: /fr/ or /nl/. If your customers are split down the middle, as in many Brussels firms, your main URL can also be a short page where visitors choose their language, with /nl/ and /fr/ behind it. That costs visitors one click, but neither language comes second.

Does everything have to be in both languages?

Not necessarily. A French site with fewer pages is fine: translate what your French-speaking customers need, and leave the rest out of the French menu. What you should avoid is a half-translated page, such as a French menu above Dutch text. Google works out the language of a page from the visible text (Google), so use one language per page.

What do you translate, and what not?

On a translated page, translate everything a visitor reads, including what's easy to forget:

• the text, menu, buttons and what's at the bottom of every page;

• the title and short description Google shows;

• the descriptions of your images for people who can't see them;

• your forms: the fields, the error messages and the confirmation email;

• the error page, your cookie banner and your privacy statement.

Don't translate: your brand and product names.

Do adapt:

• Your legal form: a BV is an SRL in French, an NV an SA, a CV an SC (Code of Companies and Associations, art. 1:5).

• Your numbers: your enterprise number stays the same. In French it's the numéro d'entreprise, and your VAT number is the numéro de TVA.

• Place names: Luik and Liège, Bergen and Mons, Brussel and Bruxelles. In Brussels your street has two names: use the French one on the French page.

Who translates, and what does it cost?

You can translate yourself, hire a translator, or let AI make a first version that someone reviews. Translators usually charge per word: ask for a price for the number of words on your site, and for what you add later. AI translates in minutes, but reviewing takes time from someone who knows the language well.

Google has nothing against AI-written text, as long as it helps visitors (Google). What Google does call spam: automatically translating other people's content to mass-produce pages (Google). Having your own texts translated and reviewed isn't covered by that. Whoever reviews the translation should watch for:

• Belgian French. AI often writes portable where a Belgian says GSM, soixante-dix where they write septante, or SIRET where it should say numéro d'entreprise.

• Your tone. In French, vous is the norm. In Dutch, too, choose whether you address your customers as u or je, and stick to it everywhere.

• Changes. If you change a price or opening hours in one language, change them in the other too.

What goes at the bottom of every page?

Your legal information: your name, your address, your email address, your enterprise number and, if you're VAT-registered, your VAT number. For a regulated profession, add your professional body, your title and your professional rules; for an accountant, for example, the ITAA, the title it gave you and a link to the professional rules. Your site must give "easy, direct and permanent" access to this information (Code of Economic Law, art. XII.6). The law doesn't say in which language. Put it in both: that way every customer finds it.

For cookie information, however, the Belgian Data Protection Authority asks for the language of your audience: if your site is aimed at French and Dutch speakers, you give it in French and Dutch (Data Protection Authority). Under the GDPR, your privacy statement must be written "using clear and plain language" (GDPR, art. 12); for a French-speaking customer, that means French. Selling online? Before the order, say in which languages the contract can be concluded (Code of Economic Law, art. XII.7).

Part 2: what you ask your web developer

You can forward this part as it is.

A separate URL for each language

Each page has its own URL in each language, not one URL that switches language based on a cookie or the browser language. Google advises against that: Googlebot, the program that reads your site for Google, usually comes from the United States and doesn't ask for a language. If it sees only Dutch at every URL, your French site doesn't exist for Google. Google also advises against putting the language at the end of the URL (?lang=fr) (Google).

Already own a French domain name? Have it redirect permanently to yourcompany.be/fr/. Your developer calls that a 301 redirect.

Translated URLs

/fr/a-propos looks more polished than /fr/over-ons, and someone searching in French recognises their own words. Leave out accents (a-propos, not à-propos). Settle the URLs before your site goes live: if you change them later, every old URL has to be redirected.

Hreflang and x-default

Hreflang tags are a few lines of code that tell Google which pages are the same in another language. Google can then show each searcher the version in their language (Google).

• Each version points to itself and to all the others; otherwise Google ignores the tags.

• The codes are nl and fr; for English it's en. Not be: that's the code for Belarusian (ISO 639).

• x-default says which page Google shows to people who speak none of your languages: your language choice page, or your English version if you have one.

No automatic redirects

Don't send anyone to a language automatically based on their browser or IP address. Google advises against it (Google), and the W3C, which sets the standards of the web, warns that you can't guess someone's language from their location (W3C). Think of a Flemish customer who uses a computer set to French at work: an automatic redirect sends them to French, even though they read Dutch.

A small notice is fine: "Cette page existe aussi en français". And if your site remembers the choice in a cookie, no consent is needed: the Belgian Data Protection Authority considers a cookie that temporarily stores the language choice strictly necessary (see Is a cookie banner mandatory?).

A language switcher without flags

A flag stands for a country, not a language (W3C). Which flag goes with French: the French one, for a firm in Brussels? Show the name of each language in that language (Nederlands, Français, English), on every page and on mobile too. And stay on the same page: someone who picks "Français" on /over-ons lands on /fr/a-propos, not on the French home page (W3C).

Checklist

What you decide:

1. Which languages, and which one at your main URL.

2. Which pages you translate.

3. Who translates and who reviews.

4. Legal information and privacy statement in every language.

What you ask your web developer:

1. A separate, translated URL for each language.

2. Hreflang in both directions, and an x-default.

3. A language switcher with language names that stays on the same page.

4. No automatic redirects.

If you build your own site with a tool like Wix or WordPress, you can usually do all this too, with a translation feature or a plugin: check the same points. At Kintsu, three languages are included in the price, with translated URLs, hreflang, a language switcher that stays on the same page and an overview of what still needs translating: see Bilingual website.

Sources

All sources accessed on 4 November 2026.

• Google Search Central, Managing Multi-Regional and Multilingual Sites

• Google Search Central, Localized Versions of your Pages

• Google Search Central, Google Search's Guidance on Generative AI Content on Your Website

• Google Search Central, Spam Policies for Google Web Search

• W3C, Guiding users to translated pages

• W3C, Indicating the language of a link destination

• Library of Congress, ISO 639 language codes

• VUB, More Dutch is spoken in Brussels, and it's spoken better, 23 May 2024

• BRUZZ on VRT NWS, Nieuwe taalbarometer, 15 May 2024 (in Dutch)

• CSA Research, Consumers Prefer their Own Language, press release of 7 July 2020

• Belgian Constitution, art. 30 (in French; Dutch on the same site)

• Flemish government, Taalwetwijzer, Principe van taalvrijheid (in Dutch)

• Code of Economic Law, art. XII.6 and XII.7 (in Dutch; French on the same site)

• Code of Companies and Associations, art. 1:5 (in Dutch; French on the same site)

• Belgian Data Protection Authority, Cookies et autres traceurs, updated 17 November 2023 (in French; also in Dutch, not in English)

• General Data Protection Regulation (GDPR), art. 12