MModelspectraIndependent AI Model Intelligence
Head-to-head · Updated 2026-09-08
Model Comparison · Head to Head

Gemini 3.1 Pro vs Claude Opus 4.8

Gemini 3.1 Pro wins on Overall, Multimodal; Claude Opus 4.8 wins on Coding. Every numeric field is compared below, with a worked monthly-cost example and a pick rule for each use case.

VendorGoogle / Anthropic
Data fields15+ dimensions
Updated2026-09-08
Read~9 min
01

Verdict at a glance

Bottom line: Choose Gemini 3.1 Pro when its stronger dimensions matter most; choose Claude Opus 4.8 when its stronger dimensions is the priority.

Choose Gemini 3.1 Pro if you…

  • Native audio and video
  • Strong scientific computing
  • Largest 2M context
  • Search integration
  • Best for: Multimodal, Scientific reasoning, Audio & video

Choose Claude Opus 4.8 if you…

  • Previous flagship still capable
  • Well-proven stability
  • Best for: Deep reasoning, Long documents, Coding
02

Head-to-head aggregate scores

Scores are 0–100, aggregated from public benchmark information and independently weighted across three leaderboards. Rank is out of 22 tracked models.

Gemini 3.1 Pro Higher overall
Google · #3 overall
Overall83
Coding74
Multimodal92
VS
Claude Opus 4.8
Anthropic · #5 overall
Overall81
Coding87
Multimodal89

Aggregated from public sources and independently weighted; methodology on the Terms page. Scores within 3 points are treated as statistically tied.

03

Specs & pricing — every field side by side

List API prices in USD per 1M tokens. The highlighted cell is the stronger value/capability on that row.

DimensionGemini 3.1 ProClaude Opus 4.8Verdict
VendorGoogle (US)Anthropic (US)Different vendors
Released2026.052026.05Claude Opus 4.8 is newer
Overall (rank)83 · #381 · #5Gemini 3.1 Pro +2
Coding74 · #987 · #4Claude Opus 4.8 +13
Multimodal92 · #289 · #6Gemini 3.1 Pro +3
Context window2M1MGemini 3.1 Pro larger
Max output128K128KTie
Effective-context9296Claude Opus 4.8 more reliable
Input $/1M$2$5Gemini 3.1 Pro cheaper
Output $/1M$12$25Gemini 3.1 Pro cheaper
Cache discountnone90% offClaude Opus 4.8 deeper
Speed~60 tok/s~40 tok/sGemini 3.1 Pro faster
TTFT0.7s1.0sGemini 3.1 Pro snappier
Function calling7888Claude Opus 4.8 ahead
Refusal rate~12%~9%Claude Opus 4.8 less restrictive
English9094Claude Opus 4.8
Chinese7578Claude Opus 4.8
Modalitiestext, image, audio, videotext, imagedifferent coverage
Open weightsNoNoBoth closed
Fine-tuningYesNo
Free tierGemini App free with limited quota; API free tier availableNo free tier
SOC2 / no-trainyes / yesyes / yes
Private deploymentNoNoNeither

Fields drawn from vendor public documentation and the Modelspectra 22-model dataset; speed varies with network, concurrency and prompt length. Verify current pricing before purchase.

04

Dimension-by-dimension analysis

Reasoning & overall intelligence

Gemini 3.1 Pro leads the overall aggregate by 2 points (83 vs 81). That is a meaningful, not marginal, edge on hard, multi-step reasoning, while Claude Opus 4.8 remains a strong generalist that is not out of its depth on routine work.

Agentic coding

This is a clear gap: Claude Opus 4.8 scores 87 against 74. On multi-file edits, SWE-style tickets and long-horizon agent loops Claude Opus 4.8 needs fewer correction turns; Gemini 3.1 Pro is still competent for scripts and assisted completion but trails as task complexity rises.

Multimodal

Gemini 3.1 Pro leads multimodal 92 vs 89. A concrete modality difference: Gemini 3.1 Pro additionally handles audio, video.

Speed & latency

Gemini 3.1 Pro is faster in interactive use: ~60 tok/s with 0.7s TTFT versus ~40 tok/s with 1.0s TTFT (about 1.5× the throughput). For conversational UIs where perceived responsiveness drives retention, that edge is a real product factor even when raw reasoning is lower.

Context: window vs usable recall

Nominal windows are 2M for Gemini 3.1 Pro and 1M for Claude Opus 4.8. Crucially, the larger nominal window does not win on usable recall: Gemini 3.1 Pro advertises 2M but Claude Opus 4.8 scores higher on effective-context (96 vs 92), i.e. it actually retains more of what it was given.

Price & total cost

Gemini 3.1 Pro is the cheaper API at $2/$12 versus Claude Opus 4.8 at $5/$25 per 1M input/output tokens — list input is about 2.5× lower. Cache discounts (Claude Opus 4.8 90%) shift the effective bill, worked out below.

Chinese vs English

English: Gemini 3.1 Pro 90 vs Claude Opus 4.8 94. Chinese: 75 vs 78. Both are US-based models; for Chinese-first workloads also compare domestic models on the leaderboard.

Tool use & ecosystem

Function-calling score: Gemini 3.1 Pro 78 vs Claude Opus 4.8 88, so Claude Opus 4.8 has the edge on structured tool use. Fine-tuning is available from Gemini 3.1 Pro. Factor in existing SDK/plugin familiarity — switching cost often outweighs a few-point tool-use gap.

05

Cost worked example — same workload, real token math

Assume a production workload of 100M input + 30M output tokens per month, with 90% of input tokens served from cache. Figures use public list prices.

Scenario · per monthGemini 3.1 ProClaude Opus 4.8Gap
List priceno cache applied$560100M in × $2  +  30M out × $12$1,250100M in × $5  +  30M out × $252.23×gap
With caching90% of inputs cache-hit$560no published cache discount$84590M cached in × $0.5  +  10M in × $5  +  30M out × $251.51×gap

Illustrative model; your input/output mix and cache-hit ratio change the result. Prices are list rates before any enterprise agreement.

06

Decision tree

IF the workload is agentic or multi-file coding and a wrong first pass is expensive  →  choose Claude Opus 4.8 (coding 87 vs 74).
IF you serve real-time users and latency is a product KPI  →  choose Gemini 3.1 Pro (~60 tok/s, 0.7s TTFT).
IF you are cost-driven at scale on routine, high-volume workloads  →  choose Gemini 3.1 Pro ($$2/$$12 per 1M in/out).
IF long-document recall has to be near-perfect  →  choose Claude Opus 4.8 (effective context 96 vs 92).
07

Frequently asked questions

Is Claude Opus 4.8 worth the higher price over Gemini 3.1 Pro?
At list the input rate is 2.5x higher, but cache discounts and output pricing narrow the effective gap. Pay the premium when Claude Opus 4.8's stronger dimensions protect revenue; for routine volume Gemini 3.1 Pro is the economical pick.
Which is better for agentic coding?
Claude Opus 4.8 is decisively stronger for coding (87 vs 74 on the aggregate). The gap shows on SWE-style multi-file tasks and long agent loops that need fewer correction turns; Gemini 3.1 Pro is fine for routine scripts.
How do costs compare at 100M tokens/month with caching?
At 100M input + 30M output with 90% of inputs cache-hit, Gemini 3.1 Pro is about $560/month and Claude Opus 4.8 about $845/month after cache discounts ($560 and $1,250 at list).
Does the bigger context window actually matter?
Nominal windows are Gemini 3.1 Pro (2M) and Claude Opus 4.8 (1M), but usable recall follows the effective-context score (92 vs 96). Prefer the higher effective-context model for long-document work where nothing can be missed.
Which one supports fine-tuning?
Gemini 3.1 Pro supports fine-tuning; Claude Opus 4.8 does not at this tier. If you plan to adapt the model to a narrow domain, that is a concrete differentiator.
Which handles multimodal inputs better?
Multimodal scores are 92 (Gemini 3.1 Pro) vs 89 (Claude Opus 4.8), with modality coverage text/image/audio/video versus text/image. Match the model to the input types your product actually receives.