Vocabulary

Custom Words

Hint the recognizer toward names and terms it would otherwise miss.

Custom Words are recognition hints. They're passed to the Whisper model as an "initial prompt" to nudge it toward names, jargon, and product terms it might otherwise mishear.

When to use

Add words the model keeps getting wrong — people's names, company and product names, technical terms, acronyms.

How it works

Custom Words bias recognition; they are best-effort, not guaranteed. The model is more likely to produce a hinted spelling, but it may still vary, especially for a Japanese reading that should map to an English spelling.

If a term must come out exactly a certain way every time, don't rely on Custom Words — use Replacements, which are deterministic.

Custom Words vs Replacements

Custom WordsReplacements
What it doesHints the recognizerSubstitutes text after transcription
ReliabilityBest-effortDeterministic
Best forHelping the model hear a termForcing an exact spelling

The two are separate screens and work together: hint with Custom Words, enforce with Replacements.