Input lists, output lists, and which one is the offer
A tool that converts material from one language to another has two language lists: what it can take in and what it can put out. The second is the offer, it is almost always the shorter, and it is usually the one not published. As of 2026-09-12.
| Side | What it limits | Cost of adding a language |
|---|---|---|
| Input | Which material can be processed | Lower |
| Output | Which markets a release can reach | Higher |
| Both | The operation as a whole | Set by the output side |
Inclusion rule. The two directions of a conversion, compared on what each constrains and on what extending it requires. Order. Input side first.
1The asymmetry is structural
Recognising speech trains on recordings of people talking, which exist in quantity for a great many languages. Producing speech needs a voice recorded and licensed for each language, and often for each variety within it.
So every dubbing product has a longer input list than output list, whether or not its pages show it. A vendor announcing a large jump in coverage has most likely extended the cheaper side.
2One figure with no direction is close to no information
A count published without a direction might describe the intake, the output or both. Combined with the usual silence about units, a reader is left with a number whose meaning is doubly unspecified.
The safest assumption is that a marketing figure describes whichever side is larger. A register cannot make that assumption, so it records the wording and notes that the direction is unstated.
3Publishing both costs a vendor the bigger number
Printing both lists means printing the smaller one beside the larger, and the smaller one is the product. That is a disclosure decision rather than a product property, and it is the clearest signal of careful documentation available in this category.
It is also cheap. Any vendor with both lists internally could publish both tomorrow, and the gap between the two would tell a buyer more than either number does alone.
4Generation products have two lists too
A tool that generates rather than converts still has an input side: the language of the script or novel it reads. Nothing in this category publishes it, which matters for a studio whose source material is not in English.
And it has an output side, which is what a finished video speaks. Where those two can differ deliberately, that is a feature worth publishing rather than an inconsistency.
An explainer about method and structure, not a count. No vendor number appears here that is not also in the register. The sourced material is on the register. Related: When the choice is made, Scripts in pictures.