Tutorials, deep dives and product notes — built for developers.
Claude Sonnet 5 ($3/$15, June 30) beats GPT-5.5 ($5/$30, April 23) on every directly comparable benchmark: +4.6 SWE-bench Pro, +2.2 Terminal-Bench 2.1, +5.2 HLE with tools. At 40% cheaper input and 50% cheaper output. Full benchmark comparison.
Claude Sonnet 5 vs Sonnet 4.6: every benchmark, every gain. +13.4 Terminal-Bench 2.1, +10.6 HLE tools, +5.1 SWE-bench Pro, +223 GDPval (beats Opus 4.8). Same $3/$15 list price. Tokenizer caveat explained. Full comparison with bar charts, radar, and gains chart — all sourced from Anthropic's Sonnet 5 System Card.
Claude Sonnet 5 (63.2% Pro, $15/1M) vs Opus 4.8 (69.2%, $25/1M). Sonnet 5 beats Opus on knowledge work (GDPval 1618 vs 1615), ties on HLE with tools (57.4% vs 57.9%), and delivers 93% of Opus capability at 60% of the price. Full benchmark comparison from Anthropic's Sonnet 5 System Card.
Claude Opus 4.8 leads every benchmark — but GLM-5.2 is within 0.7 pts on FrontierSWE and 0.8 pts on MCP Atlas. At $4.40 vs $25 per 1M (5.7× cheaper) with MIT open weights, GLM-5.2 is the first open-weight model that makes Opus look expensive. Full 8-benchmark comparison from Z.AI & LLM Stats data.
Anthropic's two best non-Mythos models face off. Claude Opus 4.8 ($25/1M, 69.2% Pro) leads Sonnet 4.6 ($15/1M) on all benchmarks by 1-13 pts. But Sonnet handles 1M context at standard pricing, costs 1.7x less, and was preferred by devs over Opus 4.5. Full sibling comparison.
Claude Opus 4.8 (69.2% Pro, $25/1M) dominates every benchmark vs Kimi K2.6 (58.6%, $4/1M) by 3-11 pts. But Kimi fights back on BrowseComp (-3.9), Agent Swarm (300 sub-agents), DeepSearchQA (92.5%), and is 6.25× cheaper. Full comparison with real benchmark data, 10-point verdict.
Claude Opus 4.8 (69.2% Pro, $25/1M, AA Index #1) vs MiniMax M3 (59.0%, $1.20/1M, open-weight + video). Opus dominates 5 of 6 shared benchmarks by 8-13 points. But M3 is 21× cheaper, open-weight, and wins BrowseComp (-4.2). Full comparison with VP of VentureBeat research plus MiniMax/Minimax blog data.
Anthropic's new Mythos-class Fable 5 (80.3% SWE-bench Pro, $50/1M) vs the outgoing flagship Opus 4.8 (69.2%, $25/1M). Fable 5 dominates every benchmark — but costs 2× more, hallucinates more, and sometimes falls back to Opus 4.8 anyway. Full 30-benchmark comparison.
The complete Claude Fable 5 review. Mythos-class for everyone. 80.3% Pro, 88.0% Terminal-Bench, 93.9% Verified. Stripe's 50M-line migration in a day. Karpathy: "major-version-bump-deserving." Simon Willison: "a beast." Safety classifiers, $10/$50 pricing, and why this is the biggest step toward AGI yet.
Claude Fable 5 ($50/1M) vs GPT-5.5 ($30/1M). Fable 5 leads all 8 coding benchmarks (+11.8 avg). GPT-5.5 counters with lower price and Batch/Flex at $15. 5× better Pro value from Fable 5. The definitive head-to-head comparison.
Claude Fable 5 ($50/1M) vs GPT-5.5 Pro ($180/1M). Fable 5 leads all 8 coding benchmarks by +11.8 pts avg. GPT-5.5 Pro fights back on BrowseComp (90.1%) and FrontierMath (39.6%) via parallel compute — but has no published Pro coding scores. Updated with separate GPT-5.5 Pro benchmarks.
Claude Opus 4.8 leads SWE-bench Pro by 8.6 points (69.2% vs 60.6%) — but Qwen 3.7 Max fights back on Terminal-Bench (69.7% vs 65.4%) and LiveCodeBench (91.6% vs 88.8%). With native Anthropic API compatibility and 3.33× lower cost, Qwen is the first model you can drop into Claude Code as a replacement.