How accurate is Spanish speech to text with local Whisper?
Spanish is one of Whisper's strongest languages. On the Whisper paper's Multilingual LibriSpeech benchmark (clean read speech), the large model reaches roughly 4-6% word error rate on Spanish - close to English and well ahead of most non-European languages. Real dictation in a normal room runs a little higher than a clean benchmark, but the takeaway holds: Spanish is production-quality on a good local model.
The accuracy depends far more on which model size you run than on whether it is local or cloud - it is the same open-source Whisper either way. Compact models (tiny, base) are not enough for Spanish dictation. Quality becomes genuinely usable at the small model, production-grade at medium, and best at large. SnailText's free tier covers the compact models; the larger Spanish-quality models are on Pro.
Where Spanish gets harder is at the dialect extremes. Neutral and Mexican Spanish transcribe cleanly; rapid Rioplatense (Argentinian) and coastal Caribbean Spanish push the error rate up a few points across every tool, local or cloud. This is a property of the audio, not the app - no current speech model fully closes that gap.
What Spanish dictation gets wrong, and what we do about it
Accented characters and ñ. A correct Spanish transcript has to preserve á é í ó ú and ñ. Whisper generally gets these right at larger sizes, but they are exactly what naive, English-tuned pipelines drop. SnailText biases toward correct Spanish orthography with a Spanish-specific initial prompt and keeps it consistent through the cleanup pass.
Inverted question and exclamation marks (¿ ¡). Spanish opens questions and exclamations with ¿ and ¡. Whisper's punctuation is inconsistent - as an autoregressive model it can slip into a no-punctuation mode and drop the opening marks. The Spanish prompt biases them back on so your questions read as questions.
Regional variety. Selecting Spanish works across Castilian, Mexican, and neutral Latin American Spanish - you do not pick a dialect. The honest limit is the fast coastal and Rioplatense accents, where every tool loses a few points. We would rather tell you that than pretend accuracy is uniform.
Why local, and why Spanish-tuned
Most dictation tools ship stock Whisper and inherit its Spanish behavior unchanged. The ones that tune per-dialect - Speechmatics, ElevenLabs Scribe - are cloud services: your audio leaves your machine. SnailText is the other combination: the same best-in-class local Whisper model everyone runs, plus a Spanish-tuned prompt and a Spanish-aware cleanup pass, running entirely on your own hardware.
That matters when what you dictate in Spanish is not casual - client notes, legal drafts, medical documentation, internal company text. Because the audio is processed in RAM and never uploaded, the privacy guarantee is the architecture, not a policy you have to trust. It also means it works on a plane or with no wifi.
If you want the whole interface in Spanish too, SnailText ships a fully Spanish UI. The dictation engine is the same; the language pages here are about dictating in Spanish, whatever language your interface is set to.