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Model comparison

Claude Opus 4.8 vs Mistral Medium 3.5 128B

Data verified

Head-to-head evidence from 22 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

78.34/100
No comparison
N/A
1 category wins0 category wins

Public leaderboard positions: Claude Opus 4.8 #5 (Supported); Mistral Medium 3.5 128B unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.8 and Mistral Medium 3.5 128B share 22 comparable benchmark results. 1 of 8 categories are comparable. 31 results are unique to Claude Opus 4.8; 3 to Mistral Medium 3.5 128B.

Updated July 23, 2026
Shared results
22
Claude Opus 4.8 only
31
Mistral Medium 3.5 128B only
3
Comparable categories
1 / 8

Treat this as a split decision. Claude Opus 4.8 makes more sense if coding is the priority or you need the larger 1M context window; Mistral Medium 3.5 128B is the better fit if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 22 shared benchmark results across 5 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Opus 4.8 and Mistral Medium 3.5 128B finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.

Claude Opus 4.8 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $1.50 input / $7.50 output per 1M tokens for Mistral Medium 3.5 128B. That is roughly 3.3x on output cost alone. Claude Opus 4.8 gives you the larger context window at 1M, compared with 256K for Mistral Medium 3.5 128B.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Opus 4.8 and Mistral Medium 3.5 128B
CategoryClaude Opus 4.8ΔMistral Medium 3.5 128B
CodingClaude Opus 4.881.1Margin← 3.5Mistral Medium 3.5 128B77.6
AgenticClaude Opus 4.880.3MarginNo overlapMistral Medium 3.5 128BNot measured
KnowledgeClaude Opus 4.862.7MarginNo overlapMistral Medium 3.5 128BNot measured
MathClaude Opus 4.853.9MarginNo overlapMistral Medium 3.5 128BNot measured
MultimodalClaude Opus 4.877.0MarginNo overlapMistral Medium 3.5 128BNot measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Opus 4.8B · Mistral Medium 3.5 128B

  1. SWE-bench Verified

    Coding
    Source ↗
    A 88.6%B 77.6%
    Winner: Claude Opus 4.8Δ 11
    SWE-bench Verified: Claude Opus 4.8 scored 88.6%; Mistral Medium 3.5 128B scored 77.6%. Claude Opus 4.8 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Opus 4.8Mistral Medium 3.5 128BComparison
Input / output priceUSD per 1M tokensClaude Opus 4.8$5 input / $25 outputMistral Medium 3.5 128B$1.5 input / $7.5 outputMistral Medium 3.5 128B has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.8Not availableMistral Medium 3.5 128BNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.8Not availableMistral Medium 3.5 128BNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.81MMistral Medium 3.5 128B256KClaude Opus 4.8 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
Terminal-Bench 2.0Source 74.6%—Not comparable
BrowseCompSource 84.3%—Not comparable
DeepSearchQASource 93.1%—Not comparable
OSWorld-VerifiedSource 83.4%—Not comparable
Finance Agent v2Source 53.9%—Not comparable
GDPval-AASource 1594929Claude Opus 4.8 leads
MCP AtlasSource 82.2%—Not comparable
ToolathlonSource 59.9%—Not comparable
Gert LabsSource 72.97%39.10%Claude Opus 4.8 leads
AA Agentic IndexSource 47.2%19.0%Claude Opus 4.8 leads
τ²-bench resultsSource 94.4%94.2%Claude Opus 4.8 leads
GDPval-AASource 54.7%21.4%Claude Opus 4.8 leads
ResearchClawBenchSource 21.1%—Not comparable
OSWorld 2.0Source 20.6%—Not comparable
AA BriefcaseSource 1347506Claude Opus 4.8 leads
AA AutomationBenchSource 48.5%—Not comparable
AA EnterpriseOps-GymSource 44.0%33.7%Claude Opus 4.8 leads
AA Harvey LABSource 91.1%69.1%Claude Opus 4.8 leads
AA Tau3 BankingSource 27.6%14.4%Claude Opus 4.8 leads
terminalBenchHardSource 58.3%33.3%Claude Opus 4.8 leads
aaTerminalBench21Source 84.6%—Not comparable
τ³-bench resultsSource —91.4%Not comparable
CodingClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
SWE-bench VerifiedSource 88.6%77.6%Claude Opus 4.8 leads
SWE-bench ProSource 69.2%—Not comparable
SWE MultilingualSource 84.4%—Not comparable
SWE MultimodalSource 38.4%—Not comparable
Terminal-Bench 2.0Source 74.6%—Not comparable
cursorBench31Source 58.4%—Not comparable
cursorBench32Source 62.3%—Not comparable
AA Coding IndexSource 74.3%46.9%Claude Opus 4.8 leads
AA-SciCodeSource 53.5%39.6%Claude Opus 4.8 leads
FrontierCode 1.1 MainSource 46.5%—Not comparable
Reasoning
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
AA-LCRSource 67.7%61.0%Claude Opus 4.8 leads
CritPtSource 20.9%0.0%Claude Opus 4.8 leads
Knowledge
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
GPQASource 93.6%—Not comparable
GPQA-DSource 93.6%—Not comparable
HLESource 57.9%—Not comparable
HLE w/o toolsSource 49.8%—Not comparable
Artificial Analysis Intelligence IndexSource 55.7%29.9%Claude Opus 4.8 leads
AA-GPQA DiamondSource 92.0%74.8%Claude Opus 4.8 leads
AA-HLESource 45.7%12.8%Claude Opus 4.8 leads
AA-Omniscience IndexSource 27.4%-36.3%Claude Opus 4.8 leads
AA-Omniscience AccuracySource 46.6%25.1%Claude Opus 4.8 leads
AA-Omniscience Hallucination RateSource 35.9%82.0%Claude Opus 4.8 leads
AA Openness IndexSource —33.3%Not comparable
Math
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
USAMO 2026Source 96.7%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 47.241%—Not comparable
FrontierMath v2 (Tier 4)Source 31.250%—Not comparable
Multilingual
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
INCLUDESource 87.6%—Not comparable
Multimodal
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
OfficeQA ProSource 66.2%—Not comparable
ScreenSpot ProSource 87.9%—Not comparable
CharXivSource 89.9%—Not comparable
CharXiv w/o toolsSource 80.5%—Not comparable
Design Arena WebsiteSource 1270—Not comparable
AA-MMMU-ProSource —64.9%Not comparable
Inst. Following
BenchmarkClaude Opus 4.8Mistral Medium 3.5 128BResult
AA-IFBenchSource 62.2%68.8%Mistral Medium 3.5 128B leads
Frequently Asked Questions (2)

Which is better, Claude Opus 4.8 or Mistral Medium 3.5 128B?

Claude Opus 4.8 and Mistral Medium 3.5 128B are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.

Which is better for coding, Claude Opus 4.8 or Mistral Medium 3.5 128B?

Claude Opus 4.8 has the edge for coding in this comparison, averaging 81.1 versus 77.6. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.

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