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Anthropic: Claude Fable 5 vs OpenAI: gpt-oss-20b

On input price, OpenAI: gpt-oss-20b is ~555.6× cheaper. Verified 2026-10-21.

Anthropic: Claude Fable 5 $10.00/$50.00vsOpenAI: gpt-oss-20b $0.018/$0.090

Verdict

On blended price (3:1 input:output), OpenAI: gpt-oss-20b is ~555.6× cheaper ($0.018/$0.090 vs $10.00/$50.00 per 1M tokens).

Pricing

Per-million-token list prices, verified 2026-10-21. Green marks the better value.

MetricAnthropic: Claude Fable 5OpenAI: gpt-oss-20b
Input / 1M$10.00$0.018
Output / 1M$50.00$0.090
Cache read / 1M$1.00$0.0090
Blended (3:1)$20.00/1M$0.036/1M
Estimated monthly costAnthropic: Claude Fable 5OpenAI: gpt-oss-20b
Chatbot10,000 reqs · 800/400 tok$280.00$0.50
Coding agent5,000 reqs · 8000/2000 tok$900.00$1.62
RAG pipeline30,000 reqs · 4000/500 tok$1950.00$3.51

Plug in your own numbers in the calculator, or paste a real bill into the Bill Shredder.

Specifications & capabilities

MetricAnthropic: Claude Fable 5OpenAI: gpt-oss-20b
Context window1M131K
Max output128K33K
Vision input✓–
Tool calling✓✓
Reasoning✓✓

Quality

Intelligence Index by Artificial Analysis (independent evaluations, 0–100).

Verified intelligence scores aren't available for both models yet. See the full leaderboard.

Performance

Measured by Artificial Analysis on live endpoints.

Speed measurements aren't available for both models yet.

Provider

Infrastructure metrics for the organizations behind these models.

MetricAnthropicOpenAI
Listed endpoints812
Reliability99.8%99.9%
Avg latency520 ms450 ms
Pricing tiersstandard, batchstandard, batch, provisioned

Full details: Anthropic: Claude Fable 5 pricing · OpenAI: gpt-oss-20b pricing