# Kimi K3 vs Fable Comparison: Cost and Performance Analysis Open model Kimi K3 competes with closed model Fable. - **Source:** [Hacker News (news.ycombinator.com)](https://brifing.si/source/13c923cd-6d99-442b-9b8b-1181f4d8cd91) - **Published:** 2026-07-21 - **Topic:** [Data & AI](https://brifing.si/c/data-ai) - **Original article:** - **On Brifing:** https://brifing.si/s/da9ebf7a-6c76-43d8-a0a7-f271842ac8ab ## Kimi K3 and Fable Comparison Kimi K3, an open-source AI model, can compete with closed models like Fable. Tests showed that K3 achieved similar accuracy rates to Fable. Particularly in long-term tasks, K3 was up to 50 times more cost-effective than Fable. ## Performance and Cost Analysis In tests on approximately 1,030 tasks, K3 and Fable performed similarly. For example, in software development tasks, K3 achieved 92.4% accuracy, while Fable reached 92.6%. However, K3 performed better in symbolic math and developer tools. ## Task Routing Method Using the oracle routing method, it was determined which model would better solve each task. This method showed that K3 was selected for 72-96% of tasks, indicating that proper routing can harness the best performance of both models. ## Cost Advantage K3 offers a significant cost advantage over Fable. Especially in long-term terminal tasks, K3 consumes far fewer tokens than Fable. For example, in software development tasks, K3 used 1.3M tokens, while Fable used only 130K tokens. ## K3 in Long-Term Tasks In terminal tasks, K3 successfully completed some tasks that Fable could not. K3's performance stood out particularly in security and crypto areas. In these tasks, K3 operated at much lower costs and delivered better results than Fable. ## Conclusion and Insights Using Kimi K3 and Fable together combines the best aspects of both models. Proper routing allows for both high accuracy rates and reduced costs. This shows that using a single model is no longer the best option. ## Sources covering this story - https://fireworks.ai/blog/kimik3-fable — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._