One of the most common questions we get at DocsRouter is: "Which model is the most cost-effective?"
The answer is complex because every provider prices things differently. OpenAI charges by "tiles" (512x512 pixels). Google charges by "image" (regardless of size). Anthropic charges by "input tokens" (where 1 image ≈ 1000 tokens).
We have normalized the data to give you a clear comparison per Standard A4 Page.
Cost Per Page (2025 Rates)
| Model | Cost per Page | Speed | Best For |
|---|---|---|---|
| Gemini 3 Flash | $0.0004 | Fast | Receipts, ID Cards, Simple Forms |
| GPT-4o Mini | $0.0015 | Medium | General Purpose |
| Claude 3.5 Sonnet | $0.0030 | Medium | Handwriting |
| GPT-5.2 | $0.0150 | Slow | Complex Legal, Zero-Shot |
| Claude 4.5 Opus | $0.0250 | Very Slow | Archival Handwriting, Art |
The Hidden Multiplier: Tokens
The image cost is just the entry fee. You also pay for the text the model reads (Input Tokens) and the JSON it writes (Output Tokens).
For a dense legal contract:
- Image Cost: $0.01 (GPT-5.2)
- Input Tokens (3000 words): $0.03
- Output Tokens (Extracted JSON): $0.01
- Total: $0.05 per page
How DocsRouter Saves You Money
DocsRouter includes a Cost Limiter middleware.
{
"strategy": "budget_first",
"max_cost_per_page": 0.005
}If you set a budget of half a cent per page, DocsRouter will automatically route your request to Gemini 3 Flash. If the document is too complex for Flash (low confidence), it will reject the request rather than blowing your budget on a pricier model.
Conclusion
Don't let cloud bills surprise you. Use DocsRouter to enforce budgets and route intelligently.