Claude 3.5 Haiku (2024-10-22) vs Gemini 3.1 Pro preview

Claude 3.5 Haiku (2024-10-22) (Anthropic, 200,000-token context) versus Gemini 3.1 Pro preview (Google Vertex AI, 1,048,576-token context). Claude 3.5 Haiku (2024-10-22) is cheaper by 66% on a blended token mix. Gemini 3.1 Pro preview uniquely supports audio input and native reasoning mode. Across 1 public benchmark we tracked, Claude 3.5 Haiku (2024-10-22) wins 0 and Gemini 3.1 Pro preview wins 1. Use the live calculator below to plug your real usage shape into both, then route the winner via Agent Command Center for shadow A/B without code changes.

Bottom line — Claude 3.5 Haiku (2024-10-22) vs Gemini 3.1 Pro preview

Claude 3.5 Haiku (2024-10-22) and Gemini 3.1 Pro preview target overlapping workloads but differ sharply on economics. Claude 3.5 Haiku (2024-10-22) runs roughly 66% cheaper on a blended input-plus-output token mix, which translates to approximately $8,400 per month at mid-market volume (100K requests/day). The gap compounds at enterprise scale, making the cost axis the first filter most teams apply when deciding between these two models.

Gemini 3.1 Pro preview ships a 1,048,576-token context window, 5.2x larger than Claude 3.5 Haiku (2024-10-22)'s 200,000 tokens. That headroom matters for long-document RAG pipelines, multi-turn agent sessions that accumulate tool-call history, and codebases where the entire repository needs to fit in a single prompt. If your average prompt stays under 200,000 tokens, the extra context on Gemini 3.1 Pro preview is insurance you may never use — and Claude 3.5 Haiku (2024-10-22) may win on other axes.

On capability surface area, the models diverge: Gemini 3.1 Pro preview supports audio input where the other does not; Gemini 3.1 Pro preview supports native reasoning mode where the other does not. These differences are binary — either your workload needs the capability or it does not. Check whether any critical path in your agent pipeline depends on a capability only one model provides before committing to a migration.

For teams evaluating both models, the recommended path is a shadow A/B test: route production traffic through an OpenAI-compatible gateway, mirror a percentage to the candidate model, score both responses with an automated evaluator (faithfulness, tool-call correctness, latency), and compare cohort-level metrics over two weeks. Future AGI Agent Command Center supports this pattern with a single `base_url` change and built-in evaluators from the ai-evaluation SDK.

Side-by-side cost

Live workload comparison

Same workload run through both models. The cheaper one is highlighted.

3,000
01,048,576
400
065,536
5,000
01,000,000
Anthropic
$609/mo
Input $0.800/M · Output $4.00/M
Google Vertex AI
$1,644/mo
Input $2.00/M · Output $12.00/M
At this workload, Claude 3.5 Haiku (2024-10-22) is 63% cheaper than Gemini 3.1 Pro preview — a savings of $1,035/month ($12,419/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
  model: claude-3-5-haiku-20241022
  provider: anthropic
fallback:
  model: gemini-3-1-pro-preview
  provider: vertex-ai
shadow: { sample_rate: 0.05 }   # mirror 5% of traffic to compare quality live
Claude 3.5 Haiku (2024-10-22) Gemini 3.1 Pro preview
Input price $0.800/M $2.00/M
Output price $4.00/M $12.00/M
Context window 200,000 1,048,576
Max output 8,192 65,536
Function calling
Vision
Audio input
Reasoning
Prompt caching
Structured output
Pricing verified May 7, 2026 Jun 2, 2026
Cheaper option
~66% cheaper than the priciest in this pair
Larger context
1,048,576 tokens
More capabilities
6 of 6 capability flags advertised

Benchmark comparison

Side-by-side public benchmark scores. Greener bar = winner.

Chatbot Arena ELOgeneral
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
1,492
GPQA Diamondreasoning⚠ different settings
Claude 3.5 Haiku (2024-10-22)
41.6%
Gemini 3.1 Pro preview
94.3%
τ-bench (retail)agent
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
90.8%
HumanEvalcode
Claude 3.5 Haiku (2024-10-22)
88.1%
Gemini 3.1 Pro preview
SWE-bench Verifiedagent
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
80.6%
MMMU-Promultimodal
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
80.5%
ARC-AGI-2reasoning
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
77.1%
MMLU-Proreasoning
Claude 3.5 Haiku (2024-10-22)
65.0%
Gemini 3.1 Pro preview
SciCodecode
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
59.0%
Humanity's Last Examreasoning
Claude 3.5 Haiku (2024-10-22)
Gemini 3.1 Pro preview
44.4%

Cost at scale: monthly spend at three usage volumes

Estimated monthly cost assuming 1,000 input + 200 output tokens per request — a realistic chat-agent shape. Adjust your own usage in the calculator at the top of this page for an exact number.

Scale Claude 3.5 Haiku (2024-10-22) Gemini 3.1 Pro preview Delta
Startup
10K requests/day
$480 /mo $1,320 /mo $840/mo
Mid-market
100K requests/day
$4,800 /mo $13,200 /mo $8,400/mo
Enterprise
1M requests/day
$48,000 /mo $132,000 /mo $84,000/mo

At enterprise scale (1M requests/day), a difference of even ~10% in unit price compounds into thousands of dollars per month. Cached input pricing and batch tiers can shift this further — both are surfaced on each model's own page.

When to choose which

Picked from the data above — not vendor marketing. Match the rules to your workload, not the other way around.

Choose Claude 3.5 Haiku (2024-10-22)

You're cost-sensitive at scale — Claude 3.5 Haiku (2024-10-22) runs ~66% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume.

Choose Gemini 3.1 Pro preview

Your workload needs long context — Gemini 3.1 Pro preview fits 1,048,576 tokens versus the other model's 200,000, enough headroom for full books, large codebases, or 100+ page documents in one shot.

Choose Gemini 3.1 Pro preview

Your agent listens to calls or voice notes — Gemini 3.1 Pro preview accepts audio input directly, the other requires an ASR preprocessing hop.

Choose Gemini 3.1 Pro preview

Your tasks involve multi-step planning or math-heavy reasoning — Gemini 3.1 Pro preview ships a native reasoning mode that explicitly thinks before responding, the other doesn't.

Choose Gemini 3.1 Pro preview

On gpqa-diamond, Gemini 3.1 Pro preview scores 52.7 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.

Capability diff — what you gain and lose on the swap

A specific list of what each model has that the other doesn't. If your workload depends on a row in Only Claude 3.5 Haiku (2024-10-22), switching to Gemini 3.1 Pro preview means re-architecting that path (and vice versa).

Only on Claude 3.5 Haiku (2024-10-22)
Nothing — everything Claude 3.5 Haiku (2024-10-22) ships is also on Gemini 3.1 Pro preview.
Only on Gemini 3.1 Pro preview
  • • Audio input
  • • Native reasoning mode
Capabilities both share (6)
  • ✓ Function calling
  • ✓ Vision input
  • ✓ PDF input
  • ✓ Streaming
  • ✓ Structured output (JSON schema)
  • ✓ Prompt caching

Benchmark winners — by the numbers

For each public benchmark that has scores for both models, the higher score and the size of the gap. Benchmarks are noisy — treat anything under a 2-point delta as effectively tied.

Benchmark Claude 3.5 Haiku (2024-10-22) Gemini 3.1 Pro preview Winner Δ
gpqa-diamond 41.6 94.3 Gemini 3.1 Pro preview +52.7

Migration considerations

Concrete differences to wire through your stack before you flip traffic from one to the other.

  • Context window changes up 424% when moving from Claude 3.5 Haiku (2024-10-22) (200,000) to Gemini 3.1 Pro preview (1,048,576). Re-check any prompt that relies on cramming long history or documents.
  • Max output tokens differ: 8,192 on Claude 3.5 Haiku (2024-10-22) vs 65,536 on Gemini 3.1 Pro preview. Long-form generation tasks may truncate differently — adjust streaming UI and chunking accordingly.
  • Gemini 3.1 Pro preview has capabilities Claude 3.5 Haiku (2024-10-22) lacks: Audio input, Native reasoning mode. Worth wiring through the agent design before commit.
  • Provider changes from Anthropic to Google Vertex AI. API authentication, rate-limit policy, regional availability, and billing all shift. Most teams route through an OpenAI-compatible gateway (e.g., Future AGI Agent Command Center) so the swap is a single `base_url` change instead of an SDK rewrite.

How to A/B test Claude 3.5 Haiku (2024-10-22) vs Gemini 3.1 Pro preview in production

If you're stuck between the two, run them side-by-side on real traffic. Four steps the Future AGI team uses internally:

  1. 1. Point your existing OpenAI SDK at https://gateway.futureagi.com/v1. No code change beyond base_url and a virtual key.
  2. 2. Mark Claude 3.5 Haiku (2024-10-22) primary, mirror 20% of traffic to Gemini 3.1 Pro preview in shadow mode. Both responses are logged; only the primary is served to users.
  3. 3. Score every shadow response with an evaluator — faithfulness, tool-call correctness, response latency, cost. Built-in evaluators in ai-evaluation cover the common axes.
  4. 4. Compare cohort-level metrics after two weeks. Switch primary when the candidate wins on what matters to your workload — and stays within your latency budget.

Full walkthrough on the Agent Command Center page.

FAQ — Claude 3.5 Haiku (2024-10-22) vs Gemini 3.1 Pro preview

Which is cheaper, Claude 3.5 Haiku (2024-10-22) or Gemini 3.1 Pro preview?

Claude 3.5 Haiku (2024-10-22) is cheaper by roughly 66% on a blended input + output token mix. Input prices are $0.800/M for Claude 3.5 Haiku (2024-10-22) versus $2.00/M for Gemini 3.1 Pro preview; output prices are $4.00/M versus $12.00/M. The exact savings depend on your input:output ratio — use the live calculator above to plug in your own request shape.

What is the context window of Claude 3.5 Haiku (2024-10-22) versus Gemini 3.1 Pro preview?

Claude 3.5 Haiku (2024-10-22) supports up to 200,000 tokens of context. Gemini 3.1 Pro preview supports up to 1,048,576 tokens. Gemini 3.1 Pro preview has the larger window by a factor of 5.2x, which matters for long-document RAG, multi-turn agent sessions, and tasks that need to keep an entire codebase in working memory.

Do Claude 3.5 Haiku (2024-10-22) and Gemini 3.1 Pro preview both support tool calling?

Yes — both Claude 3.5 Haiku (2024-10-22) and Gemini 3.1 Pro preview support native function calling. Both also support structured output via JSON schema, so an agent can be ported between them with the same tool definitions.

Which model supports prompt caching for cost reduction?

Both Claude 3.5 Haiku (2024-10-22) and Gemini 3.1 Pro preview support prompt caching. Cached input tokens are typically discounted 50–90% versus uncached input, depending on the provider. For agents with a stable system prompt + retrieval context, the cached pricing tier is the real unit economics number to track.

When should I choose Claude 3.5 Haiku (2024-10-22) over Gemini 3.1 Pro preview?

You're cost-sensitive at scale — Claude 3.5 Haiku (2024-10-22) runs ~66% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume.

When should I choose Gemini 3.1 Pro preview over Claude 3.5 Haiku (2024-10-22)?

Your workload needs long context — Gemini 3.1 Pro preview fits 1,048,576 tokens versus the other model's 200,000, enough headroom for full books, large codebases, or 100+ page documents in one shot. Your agent listens to calls or voice notes — Gemini 3.1 Pro preview accepts audio input directly, the other requires an ASR preprocessing hop. Your tasks involve multi-step planning or math-heavy reasoning — Gemini 3.1 Pro preview ships a native reasoning mode that explicitly thinks before responding, the other doesn't. On gpqa-diamond, Gemini 3.1 Pro preview scores 52.7 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.

How do I A/B test Claude 3.5 Haiku (2024-10-22) against Gemini 3.1 Pro preview in production?

Route both through an OpenAI-compatible gateway like Future AGI Agent Command Center with shadow mode enabled. Send 100% of traffic to your primary model, mirror 10–20% to the candidate, score every response with an evaluator (faithfulness, tool-call correctness, response time), and compare cohort-level metrics for two weeks. Switch when the candidate wins on the metrics that matter to your workload and stays within your latency budget.