Sonnet 5 Costs More for Long Coding Tasks
shricodev · reddit · 2026-07-11
The author tested Claude Sonnet 5 and Fable 5 on two coding tasks: adding a RAG debugger in Open WebUI, and building a browser-based Clash Royale-style game. Results show Sonnet isn't necessarily cheaper for long tasks:
- RAG debugger: Sonnet took longer but cost slightly less overall; Fable was faster and the implementation was more to the author's liking.
- Game project: Fable worked in one shot, included tests, and used Playwright for UI checks; Sonnet produced a usable appearance but had more initial issues, requiring multiple rounds of fixes, ultimately costing more time and money.
The author's conclusion: Cheaper per token doesn't mean cheaper per task completed. Sonnet 5 is significantly better than 4.6 in frontend and tool use, but token consumption and total cost can escalate quickly on complex long coding tasks.
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