MODEL VERSIONS ON THIS PAGE HAVE MOVED — CHECKED 8 OCTOBER 2026
Current line, with published API pricing per million tokens:
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OpenAI — GPT-6 Sol (paid ChatGPT), GPT-6 Luna ($0.10 / $0.50), GPT-6.1 Sol ($2.00 / $10.00), GPT-6 Astra
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Anthropic — Claude Opus 5.5, Sonnet 5.5 ($2.00 / $10.00), Haiku 5.5 ($0.10 / $0.50 below 100K), Fable 5.1
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xAI — Grok 4.3 ($1.25 / $2.50), Grok 4.7 ($2.00 / $6.00)
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Google — Gemini 3.5 Flash-Lite ($0.30 / $2.50), Gemini 3.8 Flash ($0.75 / $3.75 to 31 Dec), Gemini 4 Argon
The comparison below is kept because the reasoning still holds — how these tiers trade price against capability has not changed. The version numbers and prices have.
Current pricing table →
QUICK VERDICT — AUGUST 2, 2026
● Price: V4 Flash $0.14/M input vs Sonnet 5 $2/M (14× cheaper)
● Agentic coding: V4 Flash — Terminal-Bench 82.7%, purpose-built
● Writing quality: Sonnet 5 — best in class, adaptive thinking, 128K output
● Data residency: Sonnet 5 — Anthropic US. V4 Flash API — DeepSeek China connection (self-host on MIT weights to resolve)
● Deadline: Sonnet 5 at $2/M through August 31 only
● Open weights: V4 Flash — MIT, HuggingFace. Sonnet 5 — closed.
V4 Flash 0731 for: High-volume agentic coding at the lowest possible cost. Codex-compatible, Responses API native, MIT weights for self-hosting. 14× cheaper than Sonnet 5 at intro pricing, 21× cheaper at standard. Data residency concern resolved by self-hosting the MIT weights on Western cloud.
Claude Sonnet 5 for: Writing, analysis, complex instruction following, and any task where the quality ceiling of the best Anthropic mid-tier matters. Front-load before August 31 at $2/M. Enable prompt caching if you have a stable system prompt. Measure the tokenizer uplift on your specific content type before September 1.
Last updated August 2, 2026. Related: V4 Flash 0731 full review → · Sonnet 5 pricing deadline →