Ucs-Detect

Summary

ucs-detect Without any arguments, ucs-detect automatically tests the Unicode version and support level of a terminal emulator for Wide character, Emoji Zero Width Joiner (ZWJ) sequences, Emoji Variation Selector-16 (VS-16) sequences, and Zero-Width or combining characters by supported Language. A brief report is then printed to stdout. Installation & Usage To install or upgrade: $ pip install -U ucs-detect To use: To run a detailed test and store a yaml report to disk: $ ucs-detect --save-yaml=data/my-terminal.yaml --limit-codepoints=5000 --limit-words=5000 --limit-errors=500 Test Results More than twenty modern terminals for Windows, Linux, and Mac were tested, their results have been collected into this repository and a detailed summary is published at URL https://ucs-detect.readthedocs.io/results.html An article describing the development of ucs-detect and summarizing the results for the 1.0.4 release of ucs-detect, November 2023 is published at https://www.jeffquast.com/post/ucs-detect-test-results/ A follow-up November 2025 article discussing the results of another round of testing, including DEC Private Modes support, for release of ucs-detect 1.0.8 is published at https://www.jeffquast.com/post/state-of-terminal-emulation-2025/ Individual yaml data file reports for these terminals may also be inspected at the repository folder data, https://github.com/jquast/ucs-detect/tree/master/data Please note that results will be shared with Terminal Emulator projects and this information may become out of date as they improve their support for Unicode. Please do not expect the maintainers of ucs-detect to update these data files. If you wish for this report to be corrected for any given Terminal, please feel free to submit a pull request with an update to the yaml data files. Problem Many East Asian languages contain Wide (W) or Fullwidth (F) characters, meaning that each character occupies 2 cells instead of 1. Further, many languages contain special combining characte...