Phoenix does not currently support viewing two traces side by side in the UI for direct timeline comparison. The trace detail view allows you to inspect a single trace and its spans, but there is no built-in feature for side-by-side trace comparison or timeline overlay as of now. This limitation has been noted as a feature request by users, especially for latency optimization use cases, but it is not implemented yet (<https://github.com/Arize-ai/phoenix/issues/6760|GitHub Issue #6760>; see also <https://arize-ai.slack.com/archives/C04R3GXC8HK/p1741724335.448719|Slack discussion>).
Would you like more detail on possible workarounds or how to export trace data for external comparison?
Sources:
- <https://arize-ai.slack.com/archives/C04R3GXC8HK/p1741724335.448719|Slack discussion>
- <https://github.com/Arize-ai/phoenix/issues/6760|GitHub Issue #6760>