Claude Opus 5 vs Gemini 3.1 Flash Lite

Anthropic · US  |  Google · US · Updated June 2026

Quick verdict

Pick Claude Opus 5 for frontier reasoning at lower cost per task — anthropic reports it more than doubling opus 4.8 on frontier-bench v0.1 or agentic coding — within 0.5% of fable 5's peak cursorbench 3.2 score at half the cost per task (anthropic's figures). Pick Gemini 3.1 Flash Lite for ultra-low-latency, high-volume production workloads or most cost-efficient gemini 3 model — half the price of gemini 3 flash ($0.25/$1.50 vs $0.50/$3.00 per 1m tokens). On a tight budget at scale, Gemini 3.1 Flash Lite is the value pick.

Claude Opus 5 (Anthropic) and Gemini 3.1 Flash Lite (Google) are two of the models people most often weigh against each other in 2026. Claude Opus 5 is anthropic's July 2026 flagship at $5/$25 with a 1M window and an effort dial — near-frontier quality pitched on cost per task, not raw peak. Gemini 3.1 Flash Lite is google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.

Key differences at a glance

Side-by-side specs

SpecClaude Opus 5Gemini 3.1 Flash Lite
ProviderAnthropic (US) Google (US)
ReleasedJuly 24, 2026 March 3, 2026
Context window1M (~1,500 pages) 1M (~1,500 pages)
Price (in/out)$5/$25 per 1M tokens $0.25/$1.5 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, audio, video
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published 12.3%

Who wins what

Frontier reasoning at lower cost per task — Anthropic reports it more than doubling Opus 4.8 on Frontier-Bench v0.1

Claude Opus 5

Gemini 3.1 Flash Lite is comparatively weak here — lower reasoning and quality ceiling than Gemini 3.1 Pro and the full Gemini 3 Flash tier

Agentic coding — within 0.5% of Fable 5's peak CursorBench 3.2 score at half the cost per task (Anthropic's figures)

Claude Opus 5

Anthropic's July 2026 flagship at $5/$25 with a 1M window and an effort dial — near-frontier quality pitched on cost per task, not raw peak — and it is the newer of the two.

Computer use — surpasses Fable 5's best OSWorld 2.0 result at just over a third of the cost

Claude Opus 5

Claude Opus 5 lists computer use — surpasses Fable 5's best OSWorld 2.0 result at just over a third of the cost among its strengths; Gemini 3.1 Flash Lite does not.

Ultra-low-latency, high-volume production workloads

Gemini 3.1 Flash Lite

At $0.25/$1.5 per 1M tokens it undercuts Claude Opus 5 ($5/$25 per 1M tokens), and that gap compounds at volume.

Most cost-efficient Gemini 3 model — half the price of Gemini 3 Flash ($0.25/$1.50 vs $0.50/$3.00 per 1M tokens)

Gemini 3.1 Flash Lite

Claude Opus 5 is comparatively weak here — fast mode's throughput costs double the base price ($10/$50 per 1M)

High-volume agentic and tool-calling loops where cost per call matters

Gemini 3.1 Flash Lite

Google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash — and it runs cheaper at $0.25/$1.5 per 1M tokens.

Lowest cost at scale

Gemini 3.1 Flash Lite

At $0.25/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

Gemini 3.1 Flash Lite

At $0.25/$1.5 per 1M tokens it undercuts Claude Opus 5, and on millions of tokens that margin decides the monthly bill.

Anyone whose priority is frontier reasoning at lower cost per task — anthropic reports it more than doubling opus 4.8 on frontier-bench v0.1

Claude Opus 5

It is specifically built for that.

Anyone whose priority is ultra-low-latency, high-volume production workloads

Gemini 3.1 Flash Lite

That is its strongest area.

Claude Opus 5: where it fits

Anthropic's July 2026 flagship at $5/$25 with a 1M window and an effort dial — near-frontier quality pitched on cost per task, not raw peak. Released July 24, 2026 by Anthropic, it is built for frontier reasoning at lower cost per task — Anthropic reports it more than doubling Opus 4.8 on Frontier-Bench v0.1, agentic coding — within 0.5% of Fable 5's peak CursorBench 3.2 score at half the cost per task (Anthropic's figures), computer use — surpasses Fable 5's best OSWorld 2.0 result at just over a third of the cost, and a native effort setting (low, medium, high, xhigh, max) that trades token cost against capability on a single model.

Its trade-offs are real: behind Mythos 5 on cybersecurity exploitation and biology research, by Anthropic's own account, all launch benchmarks are Anthropic-reported and not yet independently reproduced, no published SWE-Bench Verified score, so head-to-head coding comparisons rely on Anthropic's own benchmark suite, and fast mode's throughput costs double the base price ($10/$50 per 1M). At $5 in / $25 out per million tokens, it sits in the premium price band.

Gemini 3.1 Flash Lite: where it fits

Google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash. Released March 3, 2026 by Google, it is built for ultra-low-latency, high-volume production workloads, most cost-efficient Gemini 3 model — half the price of Gemini 3 Flash ($0.25/$1.50 vs $0.50/$3.00 per 1M tokens), high-volume agentic and tool-calling loops where cost per call matters, and multimodal input across text, image, video, audio, and PDF.

Its trade-offs: lower reasoning and quality ceiling than Gemini 3.1 Pro and the full Gemini 3 Flash tier, sharp long-context degradation — MRCR v2 (8-needle) retrieval falls to ~12% at the full 1M-token window, and closed weights — not downloadable or self-hostable. At $0.25 in / $1.5 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

Claude Opus 5 and Gemini 3.1 Flash Lite overlap enough that the right pick depends on your specific job. Gemini 3.1 Flash Lite costs less per token; and each leads in its own area — Claude Opus 5 for frontier reasoning at lower cost per task — anthropic reports it more than doubling opus 4.8 on frontier-bench v0.1, Gemini 3.1 Flash Lite for ultra-low-latency, high-volume production workloads. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Claude Opus 5 and Gemini 3.1 Flash Lite without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is Claude Opus 5 or Gemini 3.1 Flash Lite better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Opus 5 leans toward frontier reasoning at lower cost per task — anthropic reports it more than doubling opus 4.8 on frontier-bench v0.1 while Gemini 3.1 Flash Lite leans toward ultra-low-latency, high-volume production workloads, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Opus 5 or Gemini 3.1 Flash Lite?

Gemini 3.1 Flash Lite is cheaper — $5/$25 per 1M tokens vs $0.25/$1.5 per 1M tokens, roughly 20× apart on input.

Which has the bigger context window?

Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both Claude Opus 5 and Gemini 3.1 Flash Lite together?

Yes — a multi-model platform like LumiChats gives you Claude Opus 5, Gemini 3.1 Flash Lite and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, Claude Opus 5 or Gemini 3.1 Flash Lite?

Claude Opus 5 — released July 24, 2026, about 5 months after Gemini 3.1 Flash Lite.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.