How to pronounce ChaCha20
cs-term community-consensus
ChaCha20 is most commonly pronounced "CHA cha twenty" (/ˌtʃɑː tʃɑː ˈtwɛn ti/). This is the widely-used reading among engineers, though edge cases exist.
"CHA-cha twenty". Bernstein stream cipher.
Source: RFC 7539
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