Last updated 26 October 2026.
Using the site
DialUpSounds is free to use. You may play, download and reuse the audio it generates for any purpose, personal or commercial, including in videos, games and ringtones. A credit link is appreciated, not required. The source code is available under the MIT license.
No warranty
The site and its output are provided "as is", without warranty of any kind. We try hard to follow the ITU-T recommendations, and we label the parts we approximate, but the audio is an educational synthesis. It is not certified test equipment and is not engineering, legal or professional advice. Do not rely on it to test, certify or interoperate with real telecommunications equipment.
Loudness
Modem sounds are loud and harsh. Playback starts at a reduced level and passes through a limiter, but set your volume with care, especially on headphones.
Trademarks and standards
ITU-T recommendation numbers identify public standards. Names such as Hayes or Bell are used only to describe historical equipment and standards; no affiliation is implied.
Advertising and affiliates
The site may in future show advertising on content pages; see the privacy policy. We will disclose any affiliate relationships.
Liability
To the extent the law allows, we are not liable for any loss arising from use of the site or its output.