API cost decision in 10 seconds

🔥Claude Opus 5 vs Fugu Ultra

Pick Claude Opus 5 when budget is the priority.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Claude Opus 5 when budget is the priority.

On the standard 1M input plus 500K output workload, Claude Opus 5 is estimated at $17.5 vs $20 for Fugu Ultra, saving $2.5 (12.5% lower).

Cost-first pickClaude Opus 5
Context-first pickBoth models
Sample savings$2.512.5%
10x traffic gap$25

The reported context window is tied, so cost and provider fit carry more weight. At 10x that traffic, the same price gap is about $25. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Claude Opus 5 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickClaude Opus 5Fugu Ultra
Input-heavy / RAG5M input + 500K outputClaude Opus 5$37.5$40
Balanced workload1M input + 1M outputClaude Opus 5$30$35
Output-heavy chatbot1M input + 5M outputClaude Opus 5$130$155
Cheaper input Tie $5 vs $5 / 1M

Both models report the same input price at $5 per 1M tokens.

Cheaper output Claude Opus 5 $25 vs $30 / 1M

Claude Opus 5 is $5 cheaper per 1M output tokens (16.7% lower; 1.2x difference).

Larger context Tie 1M vs 1M

Both models report the same context window at 1M tokens.

Sample workload Claude Opus 5 $17.5 vs $20

Claude Opus 5 is $2.5 cheaper on the standard workload (12.5% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
Claude Opus 5 Calculating… Estimated API cost
Fugu Ultra Calculating… Estimated API cost
Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

both models tie on input price; Claude Opus 5 has the lower output price; both models report the same context window. For the 1M input plus 500K output sample, Claude Opus 5 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $17.5 for Claude Opus 5 and $20 for Fugu Ultra.

Best Fit

Choose Claude Opus 5 when you care most about lower output-token price.

Choose Fugu Ultra when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Decision Notes
  • On the standard 1M input plus 500K output workload, Claude Opus 5 is estimated at $17.5 vs $20 for Fugu Ultra, saving $2.5 (12.5% lower).
  • Claude Opus 5 is $2.5 cheaper on the standard workload (12.5% lower).
  • Both models report the same input price at $5 per 1M tokens.
  • Claude Opus 5 is $5 cheaper per 1M output tokens (16.7% lower; 1.2x difference).
  • Both models report the same context window at 1M tokens.
Head-to-Head Specs
Feature🔥Claude Opus 5
(Anthropic)
Fugu Ultra
(Sakana)
Input Price
prompt tokens per 1M
$5$5
Completion Price
per 1M tokens
$25$30
Sample Workload Cost
1M input + 500K output
$17.5$20
Context Window1M1M
Release Date
Popularity#9

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionClaude Opus 5On the standard 1M input plus 500K output workload, Claude Opus 5 is estimated at $17.5 vs $20 for Fugu Ultra, saving $2.5 (12.5% lower).
High-volume input processingTieLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsClaude Opus 5Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workTieA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • Claude 3 Haiku can replace Claude Opus 5 when lower sample workload cost matters most: $0.88.
  • Claude Haiku 4.5 (batch) can replace Claude Opus 5 when lower sample workload cost matters most: $1.75.
  • Claude 3.5 Haiku can replace Claude Opus 5 when lower sample workload cost matters most: $2.8.
  • Claude Sonnet 5 (batch) can replace Claude Opus 5 when lower sample workload cost matters most: $3.5.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

Anthropic catalog

Review all tracked Anthropic models before deciding whether this matchup is the right shortlist.

Open Anthropic models

Sakana catalog

Check other Sakana models with comparable pricing, context, or release timing.

Open Sakana models
Claude Opus 5

Claude Opus 5 is Anthropic’s flagship model for demanding reasoning, coding, and long-horizon agentic work. It is particularly strong at end-to-end software tasks, code review and bug finding, visual analysis...

Fugu Ultra

Fugu Ultra is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to route...