Side-by-side technical and economic comparison between Google's Gemini 2.5 Flash and Anthropic's Claude Opus 5.
| Metric | Gemini 2.5 Flash | Claude Opus 5 | Advantage |
|---|---|---|---|
| Provider Organization | Anthropic | — | |
| Standard Input / 1M | $0.075 | $5.00 | Gemini 2.5 Flash (99% lower) |
| Cached Input / 1M | $0.019 | $0.50 | Gemini 2.5 Flash lower |
| Output / 1M | $0.30 | $25.00 | Gemini 2.5 Flash lower |
| Context Window | 1.05M | 1M | Gemini 2.5 Flash (1.05M) |
| Max Generation Tokens | 8.2k | 16.4k | Claude Opus 5 |
| Tokenizer Family | Google Gemma SentencePiece (~256k vocabulary) | Anthropic Claude BPE (~65k vocabulary) | — |
Opt for Gemini 2.5 Flash when your engineering requirements prioritize Google's ecosystem, specific tokenizer efficiencies (Calibrated Gemma Tokenizer (±3%)), or when your expected prompt-to-completion ratios favor its $0.075/M input rate.
Opt for Claude Opus 5 when looking for Anthropic's tooling integration, specific context window depth (1M tokens), or when output generation volume favors its $25/M rate.