Claude Opus 4.8 vs Gemini 3.5 Flash
Anthropic's flagship against Google's production / efficiency tier — published pricing, context windows and specs, side by side.
Claude Opus 4.8 vs Gemini 3.5 Flash: side-by-side
| Claude Opus 4.8 | Gemini 3.5 Flash | |
|---|---|---|
| Maker | Anthropic | |
| Released | 27 May 2026 | 19 May 2026 (Google I/O) |
| Tier | Flagship | Production / efficiency tier |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Max output | Up to 128,000 tokens | 65,536 tokens |
| API price (per 1M) | $5 / $25 per 1M tokens | $1.50 / $9 per 1M tokens |
| Access | Proprietary — Claude API & claude.ai | Proprietary — Gemini API (Google) |
| Best at | Long-horizon agentic work, coding, knowledge work | Agentic coding, high-volume production work at near-Pro quality |
| Standout | Current Opus flagship — same $5/$25 rate card as Opus 4.7, adaptive thinking, controllable effort levels | Beats Gemini 3.1 Pro on coding at 25% lower cost — first public Gemini 3.5 release |
Price comparison
| Model | Input (per 1M) | Output (per 1M) |
|---|---|---|
| Claude Opus 4.8 | $5.00 | $25.00 |
| Claude Opus 4.8 (fast mode) | $10.00 | $50.00 |
| Gemini 3.5 Flash | $1.50 | $9.00 |
Published benchmark figures
Each figure below is the model's own published score as listed on its AI Model Hub page. Different suites (and suite versions) are not directly comparable.
| Model | Benchmark | Published score |
|---|---|---|
| Gemini 3.5 Flash | Terminal-Bench 2.1 | 76.2% |
| Gemini 3.5 Flash | MCP Atlas | 83.6% |
| Gemini 3.5 Flash | CharXiv Reasoning | 84.2% |
| Gemini 3.5 Flash | GPQA | 82.8% |
What the table says
- Pricing. Claude Opus 4.8 lists at $5 / $25 per 1M tokens; Gemini 3.5 Flash lists at $1.50 / $9 per 1M tokens. On these published rates, Gemini 3.5 Flash's input price is 3.3x lower than Claude Opus 4.8's, and Gemini 3.5 Flash's output price is 2.8x lower than Claude Opus 4.8's. Claude Opus 4.8 also offers a fast mode at $10 / $50 per 1M tokens with up to 2.5x output speed. Cached input for Gemini 3.5 Flash lists at $0.15 per 1M tokens.
- Context. Both are in the same context class: Claude Opus 4.8 lists 1,000,000 tokens and Gemini 3.5 Flash lists 1,048,576 tokens.
- Access. Both are proprietary, hosted-API models; neither publishes weights for self-hosting.
- Benchmarks. The two model pages report results on different benchmark suites, so the published scores are not directly comparable head-to-head; the tables below list each model's own published figures.
Key takeaway
Everything above is drawn from the two models' published rate cards and spec sheets. Which one fits depends on the workload you price it against — run your own token volumes through the pricing calculator to see the monthly difference.
Full Claude Opus 4.8 overview Full Gemini 3.5 Flash overview
Frequently asked questions
Which is cheaper, Claude Opus 4.8 or Gemini 3.5 Flash?
Gemini 3.5 Flash — it lists at $1.50 / $9 per 1M tokens versus $5 / $25 per 1M tokens for Claude Opus 4.8.
Which has the bigger context window, Claude Opus 4.8 or Gemini 3.5 Flash?
They are in the same class: Claude Opus 4.8 lists 1,000,000 tokens and Gemini 3.5 Flash lists 1,048,576 tokens.
Which model is newer?
Claude Opus 4.8 is the more recent release (27 May 2026); Gemini 3.5 Flash was released 19 May 2026 (Google I/O).
Can I run Claude Opus 4.8 or Gemini 3.5 Flash locally?
No — both Claude Opus 4.8 and Gemini 3.5 Flash are proprietary models accessed through their vendors' APIs and apps; neither publishes weights.