JetBrains benchmark finds RTK token compression tool shows 7.6% cost increase on Claude Code

JetBrains measured Rust Token Killer (RTK), a compression proxy for Claude Code, and found it increased token costs by 7.6 percent at low reasoning effort (p=0.004) and showed no measurable change at high effort, contrary to RTK's advertised 60-90 percent savings, according to the JetBrains AI blog. Task quality remained unchanged in both test arms.