Perceived regression in Codex quality and higher token consumption with GPT-5.6

Open 💬 1 comment Opened Jul 10, 2026 by boss-ccc

Summary

Since switching to GPT-5.6 in Codex, I have experienced a noticeable decline in day-to-day coding quality together with apparently higher token consumption.

Observed behavior

  • The agent more often repeats questions or loses track of information already provided in the thread.
  • Small, targeted tasks sometimes trigger broader repository exploration or unrelated refactoring.
  • It spends more time explaining or exploring alternatives instead of making a precise minimal patch.
  • Cross-file understanding and continuity across turns feel less reliable.
  • Fixes can introduce new issues, reducing confidence in allowing the agent to modify code autonomously.
  • For comparable tasks, usage appears to consume more tokens than before, without a corresponding improvement in correctness or stability.

Expected behavior

  • Preserve relevant context reliably across turns.
  • Prefer the smallest necessary change and avoid unrelated edits.
  • Limit repository scans and repeated test runs when the task is narrow.
  • Use token budget efficiently and provide predictable quality for comparable tasks.
  • Make token usage more transparent, ideally broken down by repository reads, reasoning, tool calls, and generated output.

Additional note

This is primarily experiential feedback rather than a controlled benchmark. The key issue is the combination of higher perceived cost and lower confidence in the resulting code. It would be helpful if the team could compare GPT-5.6 against prior Codex models on long-thread continuity, minimal-patch behavior, unnecessary file reads, repeated tool calls, and total token usage per completed task.

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