Claude 5.5 SonnetvsFLUX.2 Klein 4B

Claude 5.5 Sonnet leads the overall Podium Score by 8.3 points (94.8 vs 86.5).Category wins: Claude 5.5 Sonnet 7 — 0 FLUX.2 Klein 4B.FLUX.2 Klein 4B is the cheaper pick ($0.01/M vs $15/M per 1M output tokens). Claude 5.5 Sonnet is faster (94 t/s vs 90 t/s).

Open in Compare Tool →View Claude 5.5 SonnetView FLUX.2 Klein 4B
Claude 5.5 SonnetDrag slider or hover to compareFLUX.2 Klein 4B
FLUX.2 Klein 4B
86.5
Coding: 0.0 · Speed: 90 t/s
Output Price: $0.01/M
Claude 5.5 Sonnet
94.8
Coding: 91.5 · Speed: 94 t/s
Output Price: $15/M
Quick VerdictAggregated 2026 Benchmark Analysis

Claude 5.5 Sonnet is rated higher overall with a Podium Score of 94.8 (vs 86.5 for FLUX.2 Klein 4B). In head-to-head domain evaluations, Claude 5.5 Sonnet outperforms in 7 of 7 benchmark categories.

Coding & Engineering
Claude 5.5 Sonnet (91.5)
Inference Speed
Claude 5.5 Sonnet (94 t/s)
Cost Efficiency
FLUX.2 Klein 4B ($0.01/M)
API Price / 1M (in · out)
Claude 5.5 Sonnet $3/M · $15/M — FLUX.2 Klein 4B $0.01/M · $0.01/M

Choose Claude 5.5 Sonnet for long documents and large codebases, and FLUX.2 Klein 4B for cost-sensitive workloads.

MetricClaude 5.5 SonnetFLUX.2 Klein 4B
Podium Score94.8 ▲86.5
Arena Elo1520 ▲1380
Intelligence Index95.0 ▲87.0
Coding91.5 ▲0.0
Math94.2 ▲0.0
Reasoning95.0 ▲25.0
Agentic89.4 ▲18.0
Knowledge88.0 ▲42.0
Multimodal96.0 ▲90.0
Long-context98.0 ▲35.0
Output speed94 t/s ▲90 t/s
Output price$15/M$0.01/M ▲
Context window1000K ▲32K
Scores aggregated from five independent leaderboards. See Methodology. More head-to-heads: Claude 5.5 Sonnet vs Claude Mythos · Claude 5.5 Sonnet vs Kimi K3.1 Pro · Claude 5.5 Sonnet vs Eleven Multilingual v3 · Claude 5.5 Sonnet vs FLUX.2 Pro
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