OpenRouter has launched Horizon Beta, an updated version of its previous model, Horizon Alpha, designed as a free stealth AI model available for tasks such as vibe coding. The release aims to improve upon Horizon Alpha’s capabilities. However, early user testing and benchmarks, including LisanBench and SVG tests, indicate that Horizon Beta performs worse than Horizon Alpha in terms of consistency and quality. Users noted that Horizon Beta tends to produce less reliable outputs, with issues such as poorly rendered shadows and inconsistent generation quality. Despite the intended improvements, Horizon Alpha remains favored for its steadier performance.