Claude Opus 4.8 vs Gemini 3.5 Flash
Compare Claude Opus 4.8 and Gemini 3.5 Flash on the metrics that decide an agent workload.
| Metric | Claude Opus 4.8 | Gemini 3.5 Flash |
|---|---|---|
| Provider | Anthropic | Google Gemini |
| Input / 1M | $5.00 | $1.50 |
| Output / 1M | $25.00 | $9.00 |
| Cache read / 1M | $0.50 (−90%) | $0.15 (−90%) |
| Reuse-adj @55% | $8.14 | $2.82 |
| Context | 1M | 1M |
| Cache capture | 93% | 81% |
| Warm TTFT | 240ms (−68%) | 150ms (−61%) |
| Quality index | 97 | 86 |
Teal marks the better value in each row. Reuse-adjusted assumes 55% prefix reuse and a 25% output share.
Pick Claude Opus 4.8 when it scores higher on the composite quality index, it captures more of the available reuse.
Pick Gemini 3.5 Flash when it is cheaper once prefix reuse is priced in, it carries the larger 1M context window, it answers faster on warm cache hits.
Claude Opus 4.8 leads on quality while Gemini 3.5 Flash leads on reuse-adjusted cost. Send latency- and budget-sensitive volume to Gemini 3.5 Flash and reserve Claude Opus 4.8 for the hard requests. Zumik's aliases route between them automatically under policy.
Claude Opus 4.8 vs Gemini 3.5 Flash, answered.
Is Claude Opus 4.8 or Gemini 3.5 Flash cheaper?
At 55% prefix reuse, Claude Opus 4.8 blends to about $8.14 per 1M tokens and Gemini 3.5 Flash to about $2.82. Gemini 3.5 Flash is cheaper on that basis.
Which has the larger context window?
Gemini 3.5 Flash has the larger window: 1M vs 1M tokens.
Which captures more reuse?
Claude Opus 4.8 shows higher measured cache capture (93% vs 81%) in the Zumik corpus.
Let an alias pick for you.
Route to whichever model wins under current policy automatically. Zumik resolves the alias to the best fit per request, so you never hard-code a loser.