Claude Opus 5.5 vs Gemini 3.5 Flash-Lite: pricing and benchmarks
Gemini 3.5 Flash-Lite is 93% cheaper on input tokens ($0.30 vs $4.00 per 1M). Gemini 3.5 Flash-Lite is 88% cheaper on output tokens ($2.50 vs $20.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.5 Flash-Lite costs $195.00 a month versus $2,200 for Claude Opus 5.5, 91% less. Epoch AI has not published a capability index score for Claude Opus 5.5 yet.
Prices verified September 26, 2026.
Which should you choose?
Epoch AI has not published a capability index score for Claude Opus 5.5 yet.
Gemini 3.5 Flash-Lite costs $0.85 per 1M tokens (3:1 input-to-output mix) vs $8.00 for Claude Opus 5.5, 89% less.
Pricing and specs
| Claude Opus 5.5 | Gemini 3.5 Flash-Lite | |
|---|---|---|
| Provider | Anthropic | |
| API model ID | claude-opus-5-5 | gemini-3.5-flash-lite |
| Input / 1M tokens | $4.00 | $0.30 |
| Cached input / 1M tokens | $0.20 | $0.03 |
| Output / 1M tokens | $20.00 | $2.50 |
| Long-context rates | — | — |
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 66K tokens |
| Batch discount | 50% off | 50% off |
Benchmarks
| Claude Opus 5.5 | Gemini 3.5 Flash-Lite | |
|---|---|---|
| Epoch Capabilities Index | — | 145.1 |
| GPQA Diamond· Science reasoning | — | 77.8% |
| FrontierMath (Tiers 1–3)· Advanced math | — | 26.0% |
| SimpleQA Verified· Factual accuracy | — | — |
| ARC-AGI-2· Abstract reasoning | — | 10.3% |
| DeepSWE· Coding | — | — |
| APEX-Agents· Agentic work | — | — |
Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks
Monthly cost for real workloads
| Workload | Claude Opus 5.5 | Gemini 3.5 Flash-Lite | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $1,400 | $145.00 | Gemini 3.5 Flash-Lite 90% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $2,200 | $195.00 | Gemini 3.5 Flash-Lite 91% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $936.00 | $94.40 | Gemini 3.5 Flash-Lite 90% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
Claude Opus 5.5 vs Gemini 3.5 Flash-Lite cost calculator
- $195.00/mo$0.0039 / request
- Claude Opus 5.5Anthropic$2,200/mo$0.04 / request
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
Claude Opus 5.5 pricing notes
Anthropic’s recommended default model for most workloads, with adaptive thinking always on.
- Cache reads cost 5% of the input price, against 10% on Claude Opus 5 and Sonnet 5.
- Cache writes cost $5 (5-minute cache) or $8 (1-hour cache) per 1M tokens.
- US-only inference (inference_geo: "us") costs 1.1x.
Gemini 3.5 Flash-Lite pricing notes
Google’s lowest-cost Gemini 3.5 model for high-volume work.
- The same input price applies to text, image, video and audio.
- Output price includes thinking tokens.
Frequently asked questions
- Is Claude Opus 5.5 cheaper than Gemini 3.5 Flash-Lite?
- Gemini 3.5 Flash-Lite is 93% cheaper on input tokens ($0.30 vs $4.00 per 1M). Gemini 3.5 Flash-Lite is 88% cheaper on output tokens ($2.50 vs $20.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.5 Flash-Lite costs $195.00 a month versus $2,200 for Claude Opus 5.5, 91% less.
- Which is more capable, Claude Opus 5.5 or Gemini 3.5 Flash-Lite?
- Epoch AI has not published a capability index score for Claude Opus 5.5 yet.
- How much does Claude Opus 5.5 cost per 1M tokens?
- Claude Opus 5.5 costs $4.00 per 1M input tokens and $20.00 per 1M output tokens, and $0.20 per 1M cached input tokens on Anthropic’s standard tier.
- How much does Gemini 3.5 Flash-Lite cost per 1M tokens?
- Gemini 3.5 Flash-Lite costs $0.30 per 1M input tokens and $2.50 per 1M output tokens, and $0.03 per 1M cached input tokens on Google’s standard tier.
- Which has the larger context window, Claude Opus 5.5 or Gemini 3.5 Flash-Lite?
- Gemini 3.5 Flash-Lite has the larger context window: 1.05M tokens versus 1M for Claude Opus 5.5.