Tutorials, deep dives and product notes — built for developers.
Claude Fable 5.2 vs Fable 5.1: 20% cheaper per token yet 15 points higher on the Artificial Analysis index, with Fable 5.2 at high effort beating Fable 5.1 at max for 30% less per task. Full vendor benchmark table, effort ladder, cost-per-task maths, speed claims and a routing guide.
GPT-6.1 Terra vs Claude Sonnet 5.5: Terra is ahead at low and medium effort, then Sonnet pulls 7.9 points ahead at max while costing 19× more per task ($7.60 vs $0.40). Full effort-ladder comparison, vendor and independent benchmarks, hallucination rates, and a routing guide.
GPT-6.1 Sol vs GPT-6.1 Terra: Terra costs half as much per token and 1.8× to 2.6× less per Artificial Analysis task at matched effort, while Sol scores 3.7 to 6.5 points higher. Effort-by-effort cost and score comparison, vendor and independent benchmarks, accuracy trade-offs, and a routing guide.
Claude Haiku 5.5 vs GPT-6 Luna: identical $0.10/$0.50 list prices, but Haiku scores higher on Artificial Analysis (43 vs 38) while Luna costs about 3× less per task at max effort. Price cliffs at 100K and 272K, vendor and independent benchmarks, effort ladder, and a routing guide.
GPT-6.1 Sol matches Claude Opus 5.5's default index score for 46% less per task and ties it at low effort for 76% less — then stops at index 52, below every Opus effort above default.
OpenAI's cheapest tier cut its price 61%, cut its hallucination rate from 93% to 77%, and lost a point on the independent index. Same-harness data on both generations, where Luna regressed, where it improved, and the ten-week price collapse.
Across all six effort levels, GPT-6 Sol scores within a point of GPT-5.6 Sol and costs about half as much per task. Same-harness data on both, the full effort ladder, where coding improved, where knowledge work regressed, and the November price cliff.
OpenAI shipped GPT-6 Sol 90 minutes after Claude Opus 5.5, at half the token price. Artificial Analysis ran both on the same tests: Sol is cheaper to any index score up to about 44, then runs out of headroom. Every benchmark, both effort ladders and the real bill.
OpenAI's GPT-6 Astra vs Anthropic's Claude Fable 5.1: every benchmark, the independent indices, real-world head-to-heads, pricing deep dive, and who actually wins your workload.
DeepSeek V4 Flash costs $0.28/1M output — that's 89× cheaper than GPT-5.5. 126.7 tok/s on Artificial Analysis. 337.3 char/s on CodingFleet. 91.6% LiveCodeBench. 79.0% SWE-bench Verified. MIT license. 1M context. The complete review of the model that makes high-volume AI coding free.