# GPT-5.5

- [DeepSeek V4 Ships: Frontier-Class Coding at 1/6th the Cost](https://sdd.sh/2026/04/deepseek-v4-ships-frontier-class-coding-at-1/6th-the-cost.md): DeepSeek V4-Pro hits 80.6% on SWE-bench Verified and 93.5% on LiveCodeBench — matching or exceeding most closed models — while costing 1/6th of Claude Opus 4.7 and releasing under the MIT license. Here's what actually matters, and what the benchmarks don't tell you.
- [GPT-5.5 'Spud' Is OpenAI's Strongest Coding Model Yet — With One Important Asterisk](https://sdd.sh/2026/04/gpt-5.5-spud-is-openais-strongest-coding-model-yet-with-one-important-asterisk.md): OpenAI's first fully retrained base model since GPT-4.5 delivers 82.7% on Terminal-Bench 2.0 and leads on most agentic evals. But on SWE-bench Pro — the benchmark that tests real-world GitHub issue resolution — Claude Opus 4.7 still leads by 5.7 points. Here's what that split actually means.