What the browser already tells you
Every request carries an Accept-Language header. It is a ranked list of the languages the person has configured, and it is sent automatically to every site they visit.
It is not perfect. Somebody using a borrowed laptop or a phone bought abroad may be carrying the wrong setting, and plenty of people never change the default their device shipped with.
For a link that would otherwise show one language to everybody, it is still a large improvement. The question is not whether it is accurate for every visitor, it is whether it is better than guessing.
Setting the rules
- Create the short link with your main version as the destination.
- Add a language rule per version, matching the language code and pointing at that page.
- Decide the default carefully. It is what everyone unmatched will see.
- Test each one by changing your own browser language, which takes two minutes and catches every mistake.
The rules live on the link rather than in the pages, which means you can change them without touching the sites they point at.
Choosing the default
The instinct is to make your own language the default. That is usually the wrong choice.
The default is what a visitor from anywhere unexpected will see. For most people working in this region that means English, because it is the version the widest set of unmatched visitors can read.
If your business is entirely local and every customer is local, the calculation is different. Look at where your clicks actually come from before deciding, rather than assuming.
When not to route
Routing is invisible, and invisible things confuse people when they go wrong.
- If somebody sends a link to a colleague who reads a different language, they will land somewhere else and neither will understand why.
- If the versions differ in content rather than only in language, routing hides the difference and people cannot get to the other one.
- If you only have one version, a rule that sends everybody to the same place is a maintenance item with no benefit.
Where any of those apply, put a visible language switch on the page instead and let people choose.
The version that works best
Route by language and also put a small language switch on each page.
The routing gets almost everybody to the right place without them doing anything. The switch rescues the ones it got wrong, including the person who was sent a link by a friend.
That combination costs one extra element in the page header and removes the entire category of complaint.
Check what actually arrives
Give each language version its own destination and the statistics will tell you the split.
This is worth looking at after a month, because the answer is frequently not what people expect. A business convinced its audience was mostly local often finds a third of its clicks arriving from outside the country entirely.
A finding like that decides which language the next piece gets written in, and that is the whole return on keeping the numbers.