Anthropic: Claude Opus 4.8 (Fast)✓ Catalog verified
Fast-mode variant of Opus 4.8 - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode
Overview
Fast-mode variant of Opus 4.8 - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode
Access: available through the official Anthropic API. Context window: 1M.
Specifications
| API identifier | anthropic/claude-opus-4.8-fast |
| Provider | Anthropic |
| Model type | Multimodal LLM |
| Context window | 1M catalog |
| Input modalities | text · image · file |
| Output modalities | text |
| Released | May 27, 2026 |
| Tokenizer | Claude |
| Moderated | Yes |
| Architecture modality | text+image+file->text |
API defaults
{
"top_k": null,
"top_p": null,
"temperature": null,
"presence_penalty": null,
"frequency_penalty": null,
"repetition_penalty": null
}Pricing
Live pricing components for anthropic/claude-opus-4.8-fast as published in the catalog.
| Pricing component | Raw unit price | Normalized | Unit |
|---|---|---|---|
| Prompt tokens | $0.00001 | $10.00 / 1M | Per input token |
| Completion tokens | $0.00005 | $50.00 / 1M | Per output token |
| Request fee | N/A | N/A | Per request |
| Image fee | N/A | N/A | Per image unit |
| Web search fee | $0.01 | $0.010000 | Per search request |
Cost calculator
Estimate monthly spend from your own token volumes.
Estimated Total Cost
$15Calculated from current list pricing in the ModelsAtlas catalog.Capabilities
| Capability | Status | What it means |
|---|---|---|
| Visual Understanding | ✓ Supported | Image and document analysis support |
| Audio Processing | Not advertised | Speech and voice aligned flows |
| Tool Calling | ✓ Supported | Supports tools / function calling |
| Self-Hosting | Not advertised | Deploy outside managed APIs |
Capability signals
Directional signals derived from model metadata and capability tags — not official benchmark submissions.
Quick start
Call Anthropic: Claude Opus 4.8 (Fast) through an OpenAI-compatible client.
from openai import OpenAI
client = OpenAI(
base_url="https://openrouter.ai/api/v1",
api_key="YOUR_API_KEY"
)
response = client.chat.completions.create(
model="anthropic/claude-opus-4.8-fast",
messages=[{"role": "user", "content": "Explain quantum physics."}]
)
print(response.choices[0].message.content)Alternatives
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| Anthropic Claude Sonnet Latest | ~anthropic | 1M | $2.00 | View → |
| Anthropic: Claude Fable Latest | ~anthropic | 1M | $10.00 | View → |
Head-to-head comparisons
Side-by-side breakdowns of Anthropic: Claude Opus 4.8 (Fast) against other frontier models.
Sources & attribution
Pricing and metadata are maintained in the ModelsAtlas catalog.
Frequently asked questions
How much does Anthropic: Claude Opus 4.8 (Fast) cost?
$10.00 per 1M input tokens and $50.00 per 1M output tokens on the official Anthropic API.
What is the context window of Anthropic: Claude Opus 4.8 (Fast)?
Anthropic: Claude Opus 4.8 (Fast) supports up to 1M tokens of context.
Does Anthropic: Claude Opus 4.8 (Fast) support tool / function calling?
Yes, Anthropic: Claude Opus 4.8 (Fast) supports tool / function calling — you can register tools and the model will emit structured tool calls.
How do I access Anthropic: Claude Opus 4.8 (Fast)?
Use the official Anthropic API with the model id `anthropic/claude-opus-4.8-fast`. See the Quick start section above for code examples.