Price difference per 1M tokens
Opus 4.8 saves $5 per 1M output tokens — 17% less than GPT-5.5
For the first time, Anthropic and OpenAI's flagship models are priced within striking distance of each other. Opus 4.8 actually has a slight pricing advantage on output tokens, while GPT-5.5 edges ahead on total context window (1.05M vs 1M). This is a genuinely competitive matchup.
Cost Comparison by Use Case
1. Chatbot (500 requests/day, 1500 input + 800 output tokens)
| Model | Input/mo | Output/mo | Total/mo |
|---|---|---|---|
| Claude Opus 4.8 | $112.50 | $300.00 | $412.50 |
| GPT-5.5 | $112.50 | $360.00 | $472.50 |
Winner: Claude Opus 4.8 — saves $60/month (13%). Output pricing makes the difference at scale.
2. Code Generation (200 requests/day, 2000 input + 1500 output tokens)
| Model | Input/mo | Output/mo | Total/mo |
|---|---|---|---|
| Claude Opus 4.8 | $60.00 | $225.00 | $285.00 |
| GPT-5.5 | $60.00 | $270.00 | $330.00 |
Winner: Claude Opus 4.8 — saves $45/month (14%). Output-heavy code generation benefits from Opus 4.8's lower output price.
3. Document Analysis (100 requests/day, 5000 input + 1000 output tokens)
| Model | Input/mo | Output/mo | Total/mo |
|---|---|---|---|
| Claude Opus 4.8 | $75.00 | $75.00 | $150.00 |
| GPT-5.5 | $75.00 | $90.00 | $165.00 |
Winner: Claude Opus 4.8 — saves $15/month (9%). Even for input-heavy workloads, the output savings add up.
4. Complex Reasoning (50 requests/day, 3000 input + 2000 output tokens)
| Model | Input/mo | Output/mo | Total/mo |
|---|---|---|---|
| Claude Opus 4.8 | $22.50 | $75.00 | $97.50 |
| GPT-5.5 | $22.50 | $90.00 | $112.50 |
Winner: Claude Opus 4.8 — saves $15/month (13%). Output-heavy reasoning tasks benefit from the pricing gap.
5. High-Volume API (5000 requests/day, 500 input + 300 output tokens)
| Model | Input/mo | Output/mo | Total/mo |
|---|---|---|---|
| Claude Opus 4.8 | $375.00 | $112.50 | $487.50 |
| GPT-5.5 | $375.00 | $135.00 | $510.00 |
Winner: Claude Opus 4.8 — saves $22.50/month (4%). At high volume with smaller outputs, the gap narrows but Opus 4.8 still wins.
Feature Comparison
| Feature | Claude Opus 4.8 | GPT-5.5 |
|---|---|---|
| Input price | $5.00 | $5.00 |
| Output price | $25.00 | $30.00 |
| Context window | 1M | 1.05M |
| Vision / Image input | Yes | Yes |
| Function calling | Yes | Yes |
| Streaming | Yes | Yes |
| Extended thinking | Yes | Yes |
| JSON mode | Yes | Yes |
| System prompts | Yes | Yes |
| Fine-tuning | Yes | Yes |
When to Choose Claude Opus 4.8
Opus 4.8 is the better choice when:
- Cost efficiency matters: 17% cheaper on output tokens — this adds up fast at scale
- Deep reasoning: Anthropic's extended thinking mode excels at complex multi-step analysis
- Nuanced language tasks: Opus 4.8 tends to produce more thoughtful, nuanced responses
- Safety-sensitive applications: Constitutional AI approach for reliable, less harmful outputs
- Migrating from Claude 4: Same Anthropic ecosystem, familiar API, minimal code changes
When to Choose GPT-5.5
GPT-5.5 is the better choice when:
- Largest context window: 1.05M tokens vs 1M — matters for very long documents
- OpenAI ecosystem: Better integration with Assistants API, tool use, and plugins
- Function calling reliability: OpenAI's function calling is more mature and battle-tested
- General-purpose tasks: Excellent across the board without specialization
- Existing OpenAI stack: If you're already using GPT-4o or GPT-5, switching costs are lower
The Deprecation Factor: Claude 4 Opus Users
If you're currently using Claude 4 Opus ($15/$75) which retired June 15, 2026, Opus 4.8 is the natural upgrade path — 67% cheaper with a 5x larger context window. The comparison with GPT-5.5 is now much closer:
| Model | Input | Output | Context | vs GPT-5.5 |
|---|---|---|---|---|
| Claude 4 Opus (deprecated) | $15.00 | $75.00 | 200K | 3x more expensive |
| Claude Opus 4.8 | $5.00 | $25.00 | 1M | 17% cheaper on output |
| GPT-5.5 | $5.00 | $30.00 | 1.05M | Baseline |
Use our free Claude Deprecation Calculator to see your exact savings when migrating from Claude 4 Opus.
Cost Optimization Tips
- Start with Opus 4.8: At $5/$25, it's the cheapest premium model with top-tier quality
- Use max_tokens: Set output limits to prevent runaway generation — output is the most expensive token type for both models
- Consider Claude Sonnet 4.6: At $3/$15, it's 40% cheaper than both flagships for most tasks
- Implement model routing: Use cheaper models (GPT-5 mini, DeepSeek V4 Flash) for simple tasks, flagships for complex ones
- Monitor quality vs cost: Track error rates to ensure you're paying for quality you actually need
Calculate your exact costs: Enter your token counts and see which model saves you more.
Try the APIpulse Calculator— See if you're overpaying for AI APIs
🎯 API Cost Score
Rate your API setup — get a letter grade in 30 seconds
🎯 Rate Your API Setup in 30 Seconds
Get an A+ to F grade on your AI API costs. See how you compare and find cheaper alternatives instantly.
Get Your Cost Score →📊 Generate Your Personalized API Cost Report
Select your model, enter your monthly spend, and get a custom savings report with cheaper alternatives — free, in 60 seconds.
Save money: 📊 Live API Pricing · Cost Optimizer — find out how much you could save by switching models. Free tool.