How to pronounce X25519
cs-term community-consensus
X25519 is most commonly pronounced "X twenty-five five one nine" (/ˌɛks ˌtwɛnti faɪv faɪv ˌwʌn ˈnaɪn/). This is the widely-used reading among engineers, though edge cases exist.
"X-twenty-five-five-one-nine". DH on Curve25519.
Source: RFC 7748
Pronouncing project and product names correctly avoids the small but persistent friction of being gently corrected during standups, conference Q&As, and team calls. Hearing the word a few times locks in the right reading better than reading IPA ever will. Pronounce is a community-maintained dictionary — every entry tagged with a confidence level and (where possible) a citable source.
Hear it from the command line
Install the CLI: git clone https://github.com/anzy-renlab-ai/pronounce.git && cd pronounce && ./install.sh
⭐ Star the project
This whole page exists because of a community-maintained TSV. If it saved you a cringey moment, drop a star.
★ Star on GitHub