GPT-5.4

In one line

The previous flagship, still very strong and a reliable known quantity - often cheaper per token than its successors.

Category scores (0-100) are WhichAI blended ratings: public category leaderboards plus editorial judgment. Guidance, not official measurements.

Alternatives worth a look

• Muse Spark 1.1 (Meta) · AA 53.2API via Meta Superintelligence Labs (Meta's first paid model, July 9, 2026)
• GLM-5.2 (Z.ai) · AA 52.6Open weights · low-cost API hosts
• GPT-5.6 Luna (OpenAI) · AA 52.3Released July 9, 2026 · API $1/$6 per 1M tokens

Artificial Analysis Intelligence Index, 2026 rebased scale (top models ~ 55-66). Snapshot: September 4, 2026 (BenchLM mirror), retrieved September 8, 2026. Specs and prices come from the OpenRouter public model list on the same date. Models nobody has measured carry no index score at all and never enter a ranking: where an estimate exists it is shown separately and labelled unmeasured. Context, price, modality and release dates come from the public OpenRouter model list (retrieved September 8, 2026) and vendor pages. Missing values are not published or not yet verified - shown as -. Sources are linked inside the app (Model guide and About > Methodology).