What Is a Confidence Score? ASR Certainty Explained

What is a confidence score? It is a number that shows how sure a recognition system is about a word or a phrase, often on a scale from zero to one. Low values point to places worth checking, but a high value does not prove the word is right.

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Key facts

Scores are estimates made by the model, so different tools use different scales and are not comparable with each other.
A word with low confidence is a good candidate for review: names, numbers and rare terms often end up there.
Wrong words can still carry a high score, particularly when two words sound identical in the spoken form.
Some tools return a score for every word, others for a whole segment, and some give none.

What it looks like

{
  "words": [
    {"word": "send",     "confidence": 0.98},
    {"word": "it",       "confidence": 0.99},
    {"word": "to",       "confidence": 0.97},
    {"word": "Okafor",   "confidence": 0.54},   // review this one
    {"word": "tomorrow", "confidence": 0.95}
  ]
}

See the full list of languages, the tools and the glossary.

Frequently asked questions

What range does a confidence score use?

Many systems report a value between zero and one, where higher means more certain. The scale is a design choice, so read the tool's own documentation first.

Can I trust a high score?

Only partly. The score expresses the model's own certainty, and a confidently written homophone, such as two words that sound the same, can still be wrong.

How do I use scores to save review time?

Sort or highlight words below a chosen threshold and listen to those first. This gives a short review list instead of a full read-through.

Is a confidence score the same as word error rate?

No. Word error rate is measured afterwards against a human reference. A confidence score is a guess the system makes about itself while recognising.

Does the Potok bot show scores?

Treat the transcript as unscored text and check names, numbers and unclear passages against the audio. Export to DOCX or TXT to correct them.

Sources

Each source was opened by hand on the date shown. Pages change, so open the source if a detail matters to you.

Speech recognition (Wikipedia), Wikipedia · checked 2026-10-18
Word error rate (Wikipedia), Wikipedia · checked 2026-10-18

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