GLM-5.3-Flash vs GPT-5.6 Luna (Xhigh)
Which is better for the money: GLM-5.3-Flash by Z AI or GPT-5.6 Luna (Xhigh) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-26.
Trade-off
Verdict
Depends on your budget
GLM-5.3-Flash scores 7.2 points higher (41.8 vs 34.6) but costs 1.7× as much to run the benchmark ($306 vs $179; both mid-range class). Pick GLM-5.3-Flash when the extra intelligence is worth the premium, otherwise GPT-5.6 Luna (Xhigh).
| Metric | GLM-5.3-Flash | GPT-5.6 Luna (Xhigh) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 41.8 | 34.6 | −17.2% GPT-5.6 Luna (Xhigh) is 17.2% less intelligent |
| Total AA cost (lower is better) | $305.52 | $179.33 | −41.3% GPT-5.6 Luna (Xhigh) is 41.3% cheaper |
| End-to-end time (lower is better) | 37.02s | 45.80s | +23.7% GPT-5.6 Luna (Xhigh) is 23.7% slower |
| Price per 1M tokens (in / out) | $0.15 / $0.50 | $0.20 / $1.20 | |
| Input modalities | Text, Image | Text, Image |
GPT-5.6 Luna (Xhigh) vs GLM-5.3-Flash: 17.2% less intelligence, 41.3% less cost to run the AA benchmark, and 23.7% slower end-to-end.
Today's Pareto frontier
Against the frontier
- GLM-5.3-Flash is off the frontier: at the same or lower cost, MiMo-V2.6-Pro scores 46.30 for $207.
- GPT-5.6 Luna (Xhigh) is off the frontier: at the same or lower cost, GPT-6.1 Terra (Medium) scores 41.30 for $175.
GLM-5.3-FlashGPT-5.6 Luna (Xhigh)Today's Pareto frontierOpen-weights frontierEvery other model
Matchup
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