Benchmarks

Claude Mythos Preview leads every major coding benchmark in 2026 — 93.9% on SWE-bench Verified — but it’s locked behind Anthropic’s invitation-only Project Glasswing. GPT-5.5 (the model OpenAI shipped instead of GPT-6) scores 88.7% on SWE-bench, costs 4x less, and is available in the API today. For most dev teams, GPT-5.5 is the only frontier option that actually ships. The ‘GPT-6’ Situation: What OpenAI Actually Shipped in April 2026 GPT-5.5 is the model OpenAI launched on April 23, 2026 — the release widely expected to carry the “GPT-6” label. Instead of a major version bump, OpenAI delivered an incremental but significant upgrade codenamed “Spud” internally, positioning it as GPT-5.5 rather than GPT-6. The decision signals OpenAI’s intent to reserve the “6” designation for a substantially larger architectural leap, similar to how GPT-4 marked a clear departure from GPT-3.5. GPT-5.5 ships in three variants — standard, Thinking, and Pro — at pricing of $5/M input and $30/M output for standard, with Pro at $30/$180. The model is available via ChatGPT, Codex CLI, and the OpenAI API from day one. Key capabilities: 60% fewer hallucinations than GPT-5.4, stronger multi-step reasoning in Thinking mode, and a 82.7% score on Terminal-Bench 2.0 that narrowly edges Claude Mythos Preview. For developers evaluating this release, GPT-5.5 is the de facto frontier option available without waitlists or partner agreements — making availability as important as raw benchmark numbers. ...

As of May 2026, GPT-6 hasn’t shipped yet — so this comparison covers what developers are actually choosing between: GPT-5.5, Claude Opus 4.7, and Gemini 3.1 Pro, while mapping where GPT-6 will likely disrupt those rankings when it lands in Q3–Q4 2026. GPT-6 vs Claude Opus 4.7 vs Gemini 3.1 Pro: Quick Verdict for Developers The current frontier model landscape in 2026 divides cleanly by developer use case: Claude Opus 4.7 dominates multi-file agentic coding with 87.6% on SWE-bench Verified and 64.3% on the harder SWE-bench Pro; Gemini 3.1 Pro owns multimodal reasoning and cost-sensitive pipelines at $2/M input — 2.5x cheaper than Claude; and GPT-5.5 leads terminal and CLI workflows with 82.7% on Terminal-Bench 2.0 and a 72% token-efficiency advantage over Claude Opus 4.7 on equivalent coding tasks. GPT-6 pre-training completed March 24, 2026 at OpenAI’s Stargate data center in Abilene, TX, with Polymarket placing 84% odds on a release before December 31, 2026. Developers building products today should choose based on their workflow specifics rather than waiting — GPT-6 is expected to deliver a 40%+ performance gain, which will reset the benchmark tables, but the architecture decisions you make now around agents, tooling, and context management will carry forward regardless of which model tops the leaderboard. ...

GPT-6 is OpenAI’s next flagship model — pre-training completed on March 24, 2026 at the Stargate facility in Abilene, Texas, but the model has not shipped to the public as of May 2026. What’s confirmed, what’s projection, and what every developer building on the OpenAI API needs to know right now. What Is GPT-6? (And Why It’s Not What Most People Think) GPT-6 is OpenAI’s next-generation flagship language model, positioned as a significant architectural leap beyond GPT-5 and GPT-5.5. It is not simply an incremental update — OpenAI’s internal roadmap treats GPT-6 as the first model built from the ground up around long-term memory, multi-step agentic workflows, and a two-tier inference system that pairs fast System-1 responses with deliberate System-2 verification. Pre-training completed on March 24, 2026, using over 100,000 liquid-cooled H100 and B200 GPUs at the Stargate data center in Abilene, Texas — a $500B infrastructure bet funded by Microsoft, SoftBank, and Oracle. What most coverage gets wrong is conflating GPT-6 with GPT-5.5. The model known internally as “Spud” was widely expected to launch as GPT-6, but OpenAI shipped it as GPT-5.5 on April 23, 2026. GPT-6 is now the model beyond that — a distinction that matters for developers forecasting API migration timelines and capability planning through 2026. ...

Claude Opus 4.6 scores 80.8% on SWE-bench Verified — the highest for any general-purpose AI model at launch — and delivers an 83% jump in ARC-AGI-2 reasoning (from 37.6% to 68.8%). Agent Teams demonstrated building a 100,000-line C compiler that boots Linux. For most developer teams the question isn’t “is it better” but “where is it better and does that justify the cost.” Benchmark Breakdown: SWE-Bench, ARC-AGI-2, and Terminal-Bench Claude Opus 4.6 is the current SWE-bench Verified leader at 80.8%, an incremental step up from Opus 4.5’s 80.9% — essentially a tie, but a tie at the top. The more dramatic story is ARC-AGI-2: Opus 4.6 scores 68.8% compared to 37.6% on Opus 4.5, an 83% relative improvement on the benchmark designed to measure fluid reasoning and novel problem-solving rather than memorized patterns. GPQA Diamond (graduate-level science questions) reached 91.3%, the highest score ever recorded on that test. These are not incremental gains — the reasoning architecture changed fundamentally. Where Opus 4.6 falls short is Terminal-Bench 2.0, scoring 65.4% against GPT-5.3 Codex’s 77.3%. Terminal-Bench measures agentic, multi-step shell and CLI tasks, and the gap here explains a lot about why GPT-5.3 Codex wins head-to-head in highly autonomous terminal workflows even as Opus 4.6 leads on SWE-bench, which tests code quality, correctness, and test-passing rates. Response latency also improved: 2.9 seconds per 1,000 tokens versus 3.2s on Opus 4.5, a 9.4% speedup that matters when running long agent chains. ...

Windsurf is 34% faster on multi-file refactors (47s vs 71s) and costs 25% less, but Cursor delivers higher code accuracy (92% vs 88%) and the industry’s best autocomplete acceptance rate at 72%. Which one you choose depends on whether you optimize for raw throughput or precision output. Why the Windsurf vs Cursor Performance Comparison Matters in 2026 The windsurf vs cursor performance comparison has become the defining question for developers choosing an AI IDE in 2026 because the two tools have diverged dramatically in their performance philosophies. Cursor crossed $2B ARR in February 2026 — up from $500M just eight months earlier — and is used by more than half of Fortune 500 companies. Windsurf (rebranded from Codeium) earned the #1 spot in LogRocket’s February 2026 AI IDE ranking, beating Cursor into third place. Both are VS Code forks with 200K standard and up to 1M token context windows, yet their benchmarks differ sharply. AI Reviews Lab ran 40+ hours of testing building a full-stack Next.js 16 application and found measurable differences across every category: refactor speed, code accuracy, hallucination resilience, and autocomplete quality. With 84% of developers now using or planning to use AI tools daily (Stack Overflow 2025), picking the wrong tool is a real productivity cost. This article cuts through marketing claims and reports what the numbers actually show. ...

Amazon Q Developer is AWS’s full-spectrum AI coding assistant that covers IDE completions, agentic task execution, security scanning, and deep AWS infrastructure context — all for $0 on the free tier or $19/user/month on Pro. If your team runs heavily on AWS, it’s the only AI tool that actually understands your real infrastructure. If you’re cloud-agnostic, there are better options. What Is Amazon Q Developer? Amazon Q Developer is AWS’s AI-powered software development assistant, launched in 2024 as the successor to Amazon CodeWhisperer and rapidly expanded into a full-spectrum tool covering IDE completions, CLI integration, AWS Console Q&A, agentic multi-file coding, security scanning, and legacy code transformation. Unlike GitHub Copilot or Cursor, which are cloud-agnostic by design, Amazon Q Developer is purpose-built for teams operating on AWS — it can answer questions about your actual infrastructure, generate CloudFormation templates from your existing account context, and identify cost anomalies in your running services. In 2026, AWS reports the transformation agent alone has saved over 4,500 developer years and driven $260 million in annual cost savings across enterprise customers. The tool is available in 11 default AWS regions plus 8 opt-in regions (19 total), supports over a dozen languages including C#, Go, Kotlin, Rust, and Terraform, and integrates with VS Code, JetBrains IDEs, and the AWS CLI. For teams where AWS represents the majority of daily work, Q Developer’s tight infrastructure integration changes the value calculation compared to every other AI coding tool on the market. ...

Windsurf SWE-1 is the first AI model family purpose-built for software engineering workflows — not just code completion. It handles multi-step agentic tasks, incomplete work states, and long-running edits across the IDE, terminal, and browser. For developers choosing an AI coding tool in 2026, SWE-1’s combination of 40%+ SWE-Bench scores and up to 950 tokens/second throughput makes it a serious alternative to Cursor and GitHub Copilot. What Is Windsurf SWE-1? The First Software-Engineering-Native AI Model Windsurf SWE-1 is a family of AI models trained specifically on software engineering tasks — including full-session agentic workflows, multi-surface tool use, and real production codebases — rather than general language modeling with coding fine-tuning added on top. Unlike GPT-4o, Claude Sonnet, or Gemini Pro — which were trained as general-purpose models and then adapted for code — SWE-1 was designed from the ground up to understand the process of software engineering, not just the syntax of code. ...

The best LLM for coding in 2026 depends on your specific workflow: GPT-5.4 leads Terminal-Bench 2.0 (75.1%) for agentic tasks, Claude Opus 4.6 dominates SWE-bench Pro (74%) for real-world GitHub issue resolution, and DeepSeek V3.2 at $0.28/M tokens delivers 90%+ quality at a fraction of the cost. There is no single winner — the right model depends on whether you’re doing code review, generation, or autonomous agentic coding. How We Evaluate Coding LLMs: Benchmark Breakdown Coding LLM evaluation in 2026 uses four primary benchmarks, each measuring a distinct capability. SWE-bench Verified (and the harder SWE-bench Pro) measures real-world GitHub issue resolution — a model receives an actual open-source repository bug report and must produce a working patch. HumanEval tests function-level code generation from docstrings, covering ~164 Python problems. LiveCodeBench uses contamination-free competitive programming problems that change weekly, making it harder to game. Terminal-Bench 2.0 is the newest addition, measuring autonomous multi-step terminal tasks — the best proxy for AI coding agents that run shell commands, install packages, and debug iteratively. SciCode tests scientific computing tasks requiring domain knowledge (physics, chemistry, biology). No single benchmark captures everything: a model that crushes HumanEval may struggle with multi-file SWE-bench refactors, and Terminal-Bench leaders often differ from LiveCodeBench leaders. The key insight: match your benchmark to your actual use case before choosing a model. ...