DeepSeek V4.1 Flash-1017: MIT-licensed 763B weights, DeepSWE 77.0 vs Opus 5's 74.0
V4.1 Flash-1017 ships 763B open weights under MIT, self-reported DeepSWE 77.0 vs Opus 5's 74.0, but trails on Terminal-Bench (42.3 vs 51.8) and HLE (42.6 vs 56.3); includes a gummy-bear physics demo.
DeepSeek just dropped V4.1 Flash-1017. Open weights. MIT license. And it beats Opus 5 on DeepSWE. This gummy-bear physics demo is one of the first things people built with it. Grab, stretch, throw, and it holds together. Not everywhere, though. Their own card has it at 77.0 vs 74.0 on DeepSWE, but Opus still leads Terminal-Bench, 51.8 vs 42.3, and HLE, 56.3 vs 42.6. The timeline will spend all weekend arguing whether that counts as "frontier." That's the wrong fight. The tell is the license. A 763B model anyone can download, fine-tune and run on their own racks. Best line on the card is a footnote: Terminal-Bench was run on the Claude Code harness. They benchmarked against Anthropic with Anthropic's own tooling, then posted the weights. Self-reported, so wait for independent evals. But "not quite frontier" and "free and close enough" are not the same threat.