{"i":18,"slug":"json-schema-vs-instructions","chart":{"id":"structured-output-time","title":"Time per call, instructions vs schema mode","subtitle":"Median; whiskers = fastest and slowest completed call","kind":"dot-range","unit":"seconds","yLabel":"Seconds","series":[{"name":"Median time per call (the three prompts pooled)","points":{"$k":["label","value","lo","hi","n"],"$r":[["Claude Haiku 4.5 (instructions) · Claude Code",9.52,5.67,17,24],["Claude Haiku 4.5 (JSON schema) · Claude Code",8.46,5.9,12.23,24],["Claude Sonnet 5.5 (instructions) · Claude Code",3.52,2.67,4.12,12],["Claude Sonnet 5.5 (JSON schema) · Claude Code",4.2,2.95,6.14,12],["GPT-6.1 Sol (low, instructions) · Codex CLI",6.21,4.2,12.27,12],["GPT-6.1 Sol (low, JSON schema) · Codex CLI",5.96,4.62,20.97,12]]}}],"note":"Whiskers are a range (fastest and slowest call), not a confidence interval. Wall time from process start to exit, so it includes CLI start-up; Codex CLI timings include its larger system prompt. The three prompts differ in length, which widens every range.","whisker":"minmax","sourceIds":["agent-structured-output"]}}