Artificial Intelligence
CER (Character Error Rate)
Also known as:
Character Error Rate
CER Metric
Updated: 2/12/2026
Metric for speech recognition and OCR at character level.
Quick Summary
CER measures errors at character level – standard for OCR and ASR without clear word boundaries.
Explanation
CER = (S + D + I) / N at character level. Particularly useful for Chinese, Japanese, etc.
Marketing Relevance
CER complements WER for OCR evaluation and multilingual ASR.
Common Pitfalls
CER and WER are not directly comparable.
Origin & History
CER emerged alongside WER for OCR evaluation in the 1990s.
Comparisons & Differences
CER (Character Error Rate) vs. WER
WER operates at word level; CER at character level.