SentencePiece

by Google

Subword tokenizer used by Whisper, SeamlessM4T, Canary.

TL;DR

Subword tokenizer used by Whisper, SeamlessM4T, Canary.

Best for building/fine-tuning ASR tokenizers without external tools. Pricing: free.

Category
Open source
License
—
Stars
—
Last push
—
Pricing
free
Platforms
Linux, macOS, Windows

What it is

Google's reference subword tokenizer. Apache-2.0.

Best for: Building/fine-tuning ASR tokenizers without external tools.
Watch out for: Bytes-only by default; check sample rate compatibility.

Install / use

pip install sentencepiece

Features

Speaker diarizationNo
Word-level timestampsYes
Streaming / real-timeNo
Languages supported99
HIPAA eligibleNo

SentencePiece vs Whipscribe

FeatureSentencePieceWhipscribe
CategoryOpen sourceTranscription APIs
Pricingfreefree beta
Speaker diarizationNoYes
Word timestampsYesYes
StreamingNoNo
Languages9999
PlatformsLinux, macOS, WindowsWeb, API, MCP

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