Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Opus 4.6
87
Gemini 3.5 Flash
87
Verified leaderboard positions: Claude Opus 4.6 #6 · Gemini 3.5 Flash #8
Treat this as a split decision. Claude Opus 4.6 makes more sense if knowledge is the priority or you would rather avoid the extra latency and token burn of a reasoning model; Gemini 3.5 Flash is the better fit if multimodal & grounded is the priority or you want the cheaper token bill.
Agentic
+4.6 difference
Coding
+9.9 difference
Knowledge
+18.2 difference
Multimodal
+6.5 difference
Claude Opus 4.6
Gemini 3.5 Flash
$5 / $25
$1.5 / $9
40 t/s
284.2 t/s
1.78s
18.55s
1M
1M
Treat this as a split decision. Claude Opus 4.6 makes more sense if knowledge is the priority or you would rather avoid the extra latency and token burn of a reasoning model; Gemini 3.5 Flash is the better fit if multimodal & grounded is the priority or you want the cheaper token bill.
Claude Opus 4.6 and Gemini 3.5 Flash finish on the same provisional overall score, so this is less about a single winner and more about where the edge shows up. The provisional headline says tie; the benchmark table is where the real choice happens.
Claude Opus 4.6 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $1.50 input / $9.00 output per 1M tokens for Gemini 3.5 Flash. That is roughly 2.8x on output cost alone. Gemini 3.5 Flash is the reasoning model in the pair, while Claude Opus 4.6 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use.
Claude Opus 4.6 and Gemini 3.5 Flash are tied on the provisional overall score, so the right pick depends on which category matters most for your use case.
Claude Opus 4.6 has the edge for knowledge tasks in this comparison, averaging 76.2 versus 58. Inside this category, AA-HLE is the benchmark that creates the most daylight between them.
Claude Opus 4.6 has the edge for coding in this comparison, averaging 64.4 versus 54.5. Inside this category, Vibe Code Bench is the benchmark that creates the most daylight between them.
Gemini 3.5 Flash has the edge for agentic tasks in this comparison, averaging 77.2 versus 72.6. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.
Gemini 3.5 Flash has the edge for multimodal and grounded tasks in this comparison, averaging 83.8 versus 77.3. Inside this category, AA-MMMU-Pro is the benchmark that creates the most daylight between them.
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