Claude Sonnet 5.5
- Input / 1M tokens
- $2.00
- Output / 1M tokens
- $10.00
- Providers
- 5
- Uptime, 24 h
- 100%
API models · Side by side
Claude Sonnet 5.5 vs GPT-6 Astra
Sonnet 5.5 costs a fifth as much as GPT-6 Astra at their base token rates. Both handle text, images and files, so the buying decision is whether Astra improves your particular work enough to cover the difference.
GPT-6 Astra
- Input / 1M tokens
- $10.00
- Output / 1M tokens
- $50.00
- Providers
- 3
- Uptime, 24 h
- 100%
The short answer
Start with Sonnet when cost is the main constraint. Compare Astra on the difficult tasks where a better result could save substantial review or rework. For an identical short-request token budget, Astra costs five times more; very long prompts widen that gap.
Estimate your monthly bill
Enter your own usage. We apply each model's current rates, including long-prompt pricing, for a 30-day month.
Try:
Claude Sonnet 5.5$270.00per month
GPT-6 Astra$1,350.00per month
A token is roughly three-quarters of an English word. Cached input, reasoning tokens, tools and media are not included.
Compare the details
Compare context, supported inputs and usage costs. Highlighted rows show a difference.
| Feature | Claude Sonnet 5.5 | GPT-6 Astra |
|---|---|---|
| Input formats | file, image, text | file, image, text |
| Output formats | text | text |
| Context / position limit | 1,000,000 | 1,050,000 |
| Endpoint output limit (tokens) | 128,000 | 128,000 |
| Developer features | Reasoning output, Completion limit, Output limit, Reasoning controls, Thinking effort, Response format, Stop sequences, Structured output, Tool selection, Tool calling, Response length | Reasoning output, Completion limit, Output limit, Reasoning controls, Thinking effort, Response format, Seed, Structured output, Tool selection, Tool calling, Response length |
| Cached input / 1M tokens | $0.10 | $1.00 |
| Cache write / 1M tokens | $2.50 | $12.50 |
| USD input / 1M tokens | $2.00 | $10.00 |
| USD output / 1M tokens | $10.00 | $50.00 |
| Available API providers | 5 | 3 |
| Best provider uptime, last 24 h | 100% | 100% |
| Model identifier | anthropic/claude-sonnet-5.5 | openai/gpt-6-astra |
API pricing
Prices are in USD per million tokens. Input is what you send; output is what the model generates. Chat subscriptions and API usage are billed separately.
GPT-6 Astra: long-prompt rates
- Long-prompt threshold: 272,000 prompt tokens. Input: $20.00 / 1M. Output: $75.00 / 1M.
Tools, images and additional reasoning can add charges. The examples below cover input and output tokens only.
Compare local modelsWhat those prices mean in practice
Each example uses the same token budget for both models. These are calculations, not measured workloads. Cache discounts, media, tools and extra reasoning are excluded.
| Workload | Claude Sonnet 5.5 | GPT-6 Astra |
|---|---|---|
| 1,000 short requestsPer request: 2,000 input + 500 output tokens | $9.00 | $45.00 |
| 100 document summariesPer request: 20,000 input + 1,000 output tokens | $5.00 | $25.00 |
| 10 long-document requestsPer request: 300,000 input + 2,000 output tokens | $6.20 | $61.50 |
Estimate = requests × (input tokens × input price + output tokens × output price) ÷ 1,000,000. Long-prompt rates are applied where the pricing data provides them. Real requests can use different amounts of output.
Beyond the price tag
The same small workload costs $9 or $45
Take 1,000 requests, each with 2,000 input tokens and a 500-token reply. Sonnet costs $9 and Astra costs $45 at base rates. That calculation holds the amount of text constant; it is not a prediction of how much either model will actually generate. For a customer-facing feature, multiply by your real request volume before deciding how much quality improvement the higher rate needs to buy.
Long documents need a separate budget
Astra switches to higher rates at the 272,000-token prompt threshold in the current pricing tiers. Sonnet has no long-prompt surcharge in the current pricing tiers. A workflow that sends an entire document collection can therefore have a different price gap from a short conversation. Use the long-document example on this page, then replace its token counts with your own. Do not budget every request at the headline rate.
A slightly larger context window may not change the choice
Astra has a 1,050,000-token context allowance; Sonnet has 1,000,000. That extra room matters only if a request genuinely needs it and fits the endpoint’s other limits. For shorter documents, it does not establish a practical advantage. Decide what material belongs in the prompt before treating the larger number as a reason to spend more.
Keep the expensive route selective
An application can use Sonnet for routine work and reserve Astra for requests that need another attempt. Define the escalation rule around the task: missing required fields, failed code checks or an answer that needs human review. Do not assume a model will recognize all its own mistakes. Keep the original request and both outputs so the additional spending can be tied to a useful outcome.
Compare the completed task, not the first reply
A cheaper answer is not economical if it needs repeated corrections, and an expensive answer is not automatically better. Compare accepted results, retries and editing time using representative examples. Keep tools, documents and response requirements consistent. That gives you a defensible reason to choose one model without relying on a generic claim about which is smarter.
Common questions
Can either model run on my laptop?
These are hosted API models. The laptop sends requests to a service; it does not load their weights locally. For a local setup, use the downloadable-model directory and What Can I Run tool.
Does the five-times price gap include everything?
It compares base input and output rates for the same token quantities. Long-prompt tiers, caching, tools, media and billable reasoning can change the actual total.