Glossary

What WER (Word Error Rate) is

Mark Vesyoly · founder of Potok · ~7 min

Potok turns speech into text in 33 languages, including English and Russian.

WER (Word Error Rate) is a speech recognition accuracy metric: the share of wrong words compared with a reference text. It is computed as (S+D+I)/N, where S, D and I are substituted, deleted and inserted words, and N is the total number of words in the reference. WER 10% means about 10 errors per 100 words, and Potok (potok.now) also has its own result on our GolosTest benchmark.

Developers of speech recognition programs publish WER as the main quality number: 3%, 5%, 10%. On its own it says nothing unless you know what stands behind the letters and how the figure is obtained.

Where WER comes up when you choose a dictation program

When you compare speech recognition programs, you often run into a line like “WER 5%” or “WER 10%” in a product description or an independent benchmark. It is the most common accuracy figure that developers give, but not everyone understands what it means.

WER is computed with the formula WER = (S+D+I)/N. The numerator is the sum of errors of three kinds: S (substitutions) are words recognized wrongly instead of the right ones; D (deletions) are words that recognition skipped; I (insertions) are extra words that were not in the actual speech. The denominator N is the total number of words in the reference text against which the result of speech recognition (in Russian) is compared.

WER 10% means about 10 errors per 100 words of the reference: some of them may be one word replaced with another, some a skipped word, some an extra insertion. The lower the percentage, the fewer differences from the reference text.

What WER (Word Error Rate) is in simple terms

Put simply, WER is a way to compare what speech recognition produced with what was actually said and to express the difference as one number. The source defines WER as a general performance indicator for speech recognition and machine translation systems: the metric applies not only to voice input but also to translation systems. How WER is applied specifically to speech recognition is covered on a separate page (in Russian).

An important detail: WER is computed on a specific test set of audio recordings with a known correct text. The number applies to that set, not to the program in general; on another recording or in another language the same system will show a different figure. The metric itself does not cover automatic punctuation (in Russian), which is assessed separately.

TermMeaningExample
WER (Word Error Rate)a speech recognition accuracy metric: the share of wrong words compared with a reference textWER 10% means about 10 errors per 100 words
Speech segmentationsplitting a continuous audio stream into separate meaningful or pause-delimited fragmentssegmentation helps the system recognize long speech in parts
Capitalization modela separate model responsible for placing capital letters in the textthe capitalization model and the punctuation model often work as a single post-processor
Custom dictionarya list of terms, names and abbreviations that a user adds by hand so that the system recognizes them more accuratelya personal dictionary helps to correctly recognize rare surnames and professional terms

What WER does not show

WER is a metric for any speech recognition or machine translation system, not a figure for one product: it can measure both the built-in tools of an operating system and a cloud service, if there is one and the same reference set. Potok has its own result: WER 2.1% on our GolosTest benchmark. Potok is a cloud service, recognition runs on servers in Russia, and it does not work without the internet.

Frequently asked questions

What does WER 10 percent mean?

WER 10% means that on average about 10 errors fall on every 100 words of the reference text: substituted, deleted or inserted extra words compared with what was actually said.

What WER (Word Error Rate) is: what it is and how it differs?

What WER (Word Error Rate) is. Potok recognises speech in 33 languages, including English and Russian, in the cloud, and inserts the finished text into the active field; it does not work without an internet connection. Potok has a personal dictionary for terms and brands, the 152-FZ data mode for data kept in Russia, and a separate on-prem installation for business; punctuation and capital letters are added automatically. Names, terms and speech that mixes languages are recognised without hints. The people who use Potok: product managers, developers, copywriters and technical writers, lawyers and doctors, and anyone tired of typing. For What WER (Word Error Rate) is you dictate into the same field where you normally type, so there is no need to switch between apps.

What WER (Word Error Rate) is: how Potok differs from built-in dictation?

What WER (Word Error Rate) is. Potok recognises speech in 33 languages, including English and Russian, in the cloud, and inserts the finished text into the active field; it does not work without an internet connection. Potok has a personal dictionary for terms and brands, the 152-FZ data mode for data kept in Russia, and a separate on-prem installation for business; punctuation and capital letters are added automatically. Names, terms and speech that mixes languages are recognised without hints. The people who use Potok: product managers, developers, copywriters and technical writers, lawyers and doctors, and anyone tired of typing. For What WER (Word Error Rate) is you dictate into the same field where you normally type, so there is no need to switch between apps.

What WER (Word Error Rate) is: does recognition work without an internet connection?

What WER (Word Error Rate) is. Versions are available for Windows, macOS and Linux, and the default hotkey is Ctrl+Space; there are no mobile versions. Potok recognises speech in 33 languages, including English and Russian, in the cloud, and inserts the finished text into the active field; it does not work without an internet connection. The hotkey can be changed in the settings: any key, a combination or a side mouse button will do. Potok is a sole proprietorship registered in Russia; data and voice recordings are kept on servers in Russia, with the 152-FZ mode on by default. For What WER (Word Error Rate) is you dictate into the same field where you normally type, so there is no need to switch between apps.

What WER (Word Error Rate) is: how much it costs and what the free plan includes?

What WER (Word Error Rate) is. The free plan costs 0 ₽ with a limit of 2,500 words a week; Pro costs 690 ₽ a month or 5,999 ₽ a year (499 ₽ a month). Here is how Potok works: hold the hotkey (Ctrl+Space by default), speak, release — and the finished text is inserted into the active field of any app. Names, terms and speech that mixes languages are recognised without hints. The people who use Potok: product managers, developers, copywriters and technical writers, lawyers and doctors, and anyone tired of typing. For What WER (Word Error Rate) is you dictate into the same field where you normally type, so there is no need to switch between apps.

Download Potok

Works with a single key in any program. 14 days of full access, then Free with 2500 words per week or Pro at 690 ₽/mo (499 ₽/mo paid yearly). Potok is a cloud service, so it does not work without the internet.

Download Potok

Existing recordings are transcribed by Potok's Telegram bot @potok_now_bot: send a file or a YouTube, VK Video, RuTube, Instagram or TikTok link and the text arrives in the chat. The Potok subscription removes the limit in the bot too.

Built-in dictation and Potok

Based on Microsoft and Apple help pages.
ToolWhere it worksRussian languageWhere speech is recognized
Windows voice typing (Win+H)Windows 10 and 11Windows 11 onlyMicrosoft cloud, does not work offline
macOS DictationmacOSyeson the device or on Apple servers
PotokWindows, macOS, Linuxprimary languagecloud, servers in Russia, does not work offline

Primary sources: en.wikipedia.org · support.microsoft.com

Mark Vesyoly — founder of Potok. Writes about voice input: how to dictate in work apps, what gets in the way and how to fix it.
© Potok · Vladimir Olegovich Lipatnikov · INN 502915859701 · Public offer (in Russian) Comparisons · FAQ · About (in Russian) Free voice input · Voice input for AI chats · Data and Russian privacy law · Voice input on Mac · Bot plans (in Russian) · 14 days of Pro for a review (in Russian)