f4x Speech Recognition

f4x Automatic
Speech Recognition

„…best detection performance in the test …“
c´t 17/21

Register now and try 60 minutes of speech recognition for free

For interviews – test it free of charge!

For interviews, podcasts, zoom recordings… etc. f4x runs directly in the browser. Your uploaded data is secure and GDPR compliant. Every new registered account gets 60 minutes of speech recognition for free.

  • GDPR compliant infrastructure
  • Server in Germany
  • without training and learning effort
  • especially for interviews

You need more
time quota?

That can f4xAll features of automatic speech recognition

  • Automatically generate a text from speech in an audio or video file
  • 1 hour interview is completed after about 1 hour of processing time.
  • GDPR-compliant implementation on servers in Germany and encrypted upload and download
  • Automatic speaker discrimination and separation of speakers into their own paragraphs
  • Upload multiple files at once in popular audio and video formats (wav, mp3, aac, ogg, mpeg, m4a, mp4, flac)
  • Especially for natural speech e.g. in interviews, podcasts or even dictations
  • Cross-platform use via browser on all operating systems and mobile devices.
  • Billing by the minute according to the amount of material and no subscription
  • Download as Word file (DOCX), for f4transcript (RTF) and as subtitle (SRT)

For recording in 48 languages

  • English(UK&US)
  • Bashkir
  • Basque
  • Belarusian
  • Bulgarian
  • Cantonese
  • Catalan
  • Croatian
  • Czech
  • Danish
  • Dutch
  • Esperanto
  • Estonian
  • Estonian
  • Finnish
  • French
  • Galician
  • German
  • Greek
  • Hindi
  • Hungarian
  • Interlingua
  • Italian
  • Japanese
  • Korean
  • Latvian
  • Lithuanian
  • Malay
  • Mandarin
  • Marathi
  • Mongolian
  • Norwegian
  • Polish
  • Portuguese
  • Romanian
  • Russian
  • Slovakian
  • Slovenian
  • Spanish
  • Swedish
  • Tamil
  • Thai
  • Turkish
  • Ukrainian
  • Uyghur
  • Vietnamese
  • Welsh

Without surcharge Functions for special applications

  • Sharing of a quota by many users on the basis of a company or domain account
    (if you are interested, please contact us by e-mail).
  • Automatic time stamps in the format #00:00:00-0#, optionally at the beginning or end of the paragraph
  • Pause detection by dot character (.) or exact second indication
  • Specification of own word lists for better recognition of technical terms within the recording

f4x 2023 EngineBest recognition performance

c’t already certified 2021 “best detection performance in the test”.
(c´t 17/21). In October 2022, we completely renewed f4x and improved the recognition by about 50%. Good transcripts are now generated even from challenging shooting situations. This significantly reduces correction times.

Test f4x now with your data.
We give you 60 minutes contingent for new registration.

We maintain high safety standards GDPR compliant

We pay attention to high security standards and transparent infrastructure so that your data is processed by us in compliance with GDPR.

Your data will be used exclusively for speech recognition and not for other purposes or even passed on. The transmission of your data is already encrypted during the upload.

Read our f4x procedure concept (submitted to the Hessian Data Protection Commissioner) here.

Speech recognition runs exclusively on ISO-27001 certified servers in Germany.

Immediately after the conversion, the recordings are deleted. The text file is stored in encrypted form until collection. After that, the data is deleted from our servers. The finished transcripts are then only available locally to you as a text file.

By the way, our servers not only run securely, but 100% with climate-neutral energy from hydropower.


No subscriptions,
No time limit,
Billing by the minute according to material length,
contingent can be used in any time.

from 5,86 € per hour

Arrow Down Top

100 hours
  2 hours 5 hours 15 hours 50 hours 200 hours
studying / doctorate 22 €
11 €/h
44 €
8,80 €/h
88 €
5,86 €/h
all others 33 €
16,50 €/h
55 €
11 €/h
144 €
9,60 €/h
444 €
8,88 €/h
888 €
8,88 €/h
1555 €
7,78 €/h

Prices incl. VAT

Billing by the minute

Voice recognition requires a quota, which you can buy in hourly packages and redeem in your account.

Billing is per minute per uploaded material,

the quota can be used flexibly and does not expire.

No subscriptions or similar standing payments.

You need
time quota?

Flexible optionsFor projects and companies

If you purchase 100 hours or more, you can receive them on request as any combination of individual contingent codes. Flexible and can be used independently of time. You can use these codes in your project or pass them on to external employees or students.

We are also happy to set up domain accounts for institutions. All users with a common e-mail domain, e.g. …@stud.uni-example.com can use a common quota. Uncomplicated to set up, no further administration necessary.

Please contact us by email before purchase.

f4transkriptCorrection software (optional)

  • Correct listening to transcripts at variable speed.
  • Easily adjust timestamps and speaker names.
  • Text modules for inserting transcription characters.
  • USB foot switch support

keep in mind…FAQ

The upload takes a very long time or is cancelled. What could be the reason for this?

Manchmal kann es mehrere Stunden dauern, bis eine Datei vollständig hochgeladen ist. Das hat nicht unbedingt etwas mit der Länge der Datei zu tun, sondern meist mit der Dateigröße. Wenn Ihre Dateien größer als 1 GB (1000 MB) sind, ist es ratsam, sie vor dem Hochladen zu verkleinern. Dies kann z.B. durch das Umwandeln einer Videodatei in eine reine Audiodatei oder durch das Komprimieren einer großen Audiodatei in mp3 mit 192kBit geschehen (bspw. mit Switch von NCH). Sollte der Upload dennoch mehrere Stunden dauern, z.B. weil Ihre Internetverbindung sehr langsam oder unser Server überlastet ist, kann es sein, dass Sie ungewollt ausgeloggt werden und der Upload nicht erfolgreich abgeschlossen wurde. Starten Sie in diesem Fall den Upload zu einem späteren Zeitpunkt erneut und versuchen Sie ggf. eine schnellere Internetverbindung oder eine kleinere Dateigröße.

Will I be charged for incorrect or incomplete uploads?

Unsuccessful uploads are not charged, but are initially noted as reserved. The credit will be credited back to you after a maximum of 24 hours. You can then start the upload again at a later time.

I have reset my password and now my transcripts have disappeared.

If you have not yet downloaded your transcripts and need to change your password, these transcripts will be deleted. As your files are encrypted with your old password, existing transcripts can no longer be opened after resetting the password. Consequently, all existing transcripts will be deleted when the password is reset, as no one will be able to read them. Any lost quota will be booked back to you and you can have the transcripts generated again at no extra cost. We take the security of transcript data very seriously. In this case, this means a small loss of convenience, but significantly more security for your data.

“File not supportet”, what does that mean?

Some audio or video files have been created in a format that is not supported by f4x. Unfortunately, this is possible regardless of the file extension. For example, an Mp3 file may have been created in very different ways. If your files are not supported by f4x, you can convert them using the freeware version of NCH Switch or numerous other programmes. Stereo MP3 with 192kBit fixed (not variable) bit rate has proven to be quite reliable here.

No speaker have been detected

Very rarely (< 1%) does our speech recognition system fail to recognise that different speakers can be heard on a recording (e.g. in interviews with twins). In such a case, the transcript looks like a very long continuous text without paragraph breaks. Even uploading the recording again would not produce a better result. In this case, it is necessary to insert paragraphs automatically during the correction process wherever there has been a change of speaker and to insert the names of the speakers and, if necessary, time stamps. The easiest way to do this is directly in f4transcript – the names of the speakers can be entered there and automatically inserted alternately when there is a paragraph change. Timestamps are then also automatically entered at the end of the paragraph.

Multiple languages in one file?

When uploading a file to f4x, you must specify which language is to be recognised in this recording. If the language changes in a recording, e.g. constantly from German to English and back to German, f4x cannot implement this correctly and will only recognise the language you have preselected and potentially leave other parts blank or insert unsuitable content.


    Your cart is emptyBack to the shop
      Calculate Shipping