Fact · Speech recognition
100.00percent word error rate
In our October 2026 benchmark on a Mac with an M2 Pro, Apple SpeechTranscriber had a word error rate of 100.00 percent on 100 Portuguese recordings from the FLEURS test set.
Measured by us on October 19, 2026, from 100 recordings
Our own measurement
This number comes from our benchmark, not from another publication. The full record (the setup, every recording's checksum, every transcript and timing) is published, so you can recompute it.
- What it measures
- Apple's on-device speech model in macOS 26 (SpeechAnalyzer with a SpeechTranscriber module, transcription preset), with the locale given (en-US, de-DE, fr-FR, es-MX, it-IT, pt-BR). The recordings are read sentences (FLEURS, Google, 2022), selected by a fixed rule before any engine ran. Run on macOS 26.6.2, 16 GB of memory.
- How it is measured
- Word error rate = 2,346 word errors / 2,346 reference words = 100.00 percent, over 100 recordings; the engine's text and FLEURS's reference sentence are normalized the same way (NFKC, lowercase, words as runs of letters and digits).
- What it does not show
- Read Wikipedia sentences in a quiet setting, scored without any extra text normalization for numbers or spelling variants, so a correct '25' against a reference 'twenty-five' counts as an error for every engine alike. Dictated speech, accents and noise differ.
In the data
A row of On-Device Speech Recognition Benchmark on a Mac, as Apple SpeechTranscriber, Portuguese: 100 percent.
- Engine
- Apple SpeechTranscriber
- Maker
- Apple
- Language
- Portuguese
A row of Speech Recognition Accuracy: Word Error Rates, as Apple SpeechTranscriber, Portuguese (our test): 100 percent.
- System
- Apple SpeechTranscriber
- Kind
- Built-in dictation
- Test set
- FLEURS
- Language
- Portuguese
- Speech
- Clean read speech
- Year
- 2026
Used to calculate
- The speech recognition word error rates dataset holds 597 data points, each a published figure traced to its source.
- The speech recognition word error rates dataset draws on 32 distinct sources.
- In the on-device speech recognition word error rates on FLEURS dataset, the 6 published figures for “Apple SpeechTranscriber” have a median of 6.66 percent, ranging from 4.15 to 100.
- The on-device speech recognition word error rates on FLEURS dataset holds 26 data points, each a published figure traced to its source.