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Compare / head-to-head

Claude Fable 5.1vsGPT-5.6 Terra

Claude Fable 5.1 leads 4 of 4 shared benchmarks. GPT-5.6 Terra is 4.3x cheaper per token. GPT-5.6 Terra has the larger context window (1.1M tokens).

Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.

Shared benchmarks
4 – 0
Claude Fable 5.1 leads
Cheaper per token
GPT-5.6 Terra
4.3x cheaper, input + output
Larger context
GPT-5.6 Terra
1.1M tokens
Provider uptime (30d)
100% · 95.5182%
Anthropic · OpenAI
Claude Fable 5.1
Anthropic · released 2026-09-01
textvision
Context
1M
Max out
128K
Input /1M
$10
Output /1M
$50
Cached /1M
$0.25
Scores
8 · 5 core
GPT-5.6 Terra
OpenAI · released 2026-07-09
textvision
Context
1.1M
Max out
128K
Input /1M
$2
Output /1M
$12
Cached /1M
$0.2
Scores
8 · 6 core
Quality

Benchmark matrix

BenchmarkClaude Fable 5.1GPT-5.6 TerraΔEdge
Reported by both · 4
FrontierMath Tier 4 v2 (Epoch AI run)87.8% epoch70.7% epoch+17.1 ptClaude Fable 5.1
FrontierMath Tiers 1-3 v2 (Epoch AI run)90.2% epoch86% epoch+4.2 ptClaude Fable 5.1
OTIS Mock AIME 2024-2025 (Epoch AI run)100% epoch99.7% epoch+0.3 ptClaude Fable 5.1
SimpleQA Verified70.8% epoch43.2% epoch+27.6 ptClaude Fable 5.1
Only Claude Fable 5.1 reports · 4
Humanity's Last Exam (no tools)60.9% not reported
CursorBench 3.2.073.4% not reported
GDPval-AA v21853 not reported
Terminal-Bench Science 0.152.6% not reported
Only GPT-5.6 Terra reports · 3
GPQA Diamondnot reported92.9%
DeepSWE v1.1not reported69.6%
SWE-Bench Pronot reported63.4%
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Fable 5.1 minus GPT-5.6 Terra in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing

Side by side

SpecClaude Fable 5.1GPT-5.6 TerraEdge
Context window1M tokens1.1M tokensGPT-5.6 Terra
Max output128K tokens128K tokensTie
Input price / 1M$10 $2 GPT-5.6 Terra
Output price / 1M$50 $12 GPT-5.6 Terra
Cached input / 1M$0.25 $0.2 GPT-5.6 Terra
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$60$14GPT-5.6 Terra
Modalitiestext · visiontext · visionTie
Released2026-09-012026-07-09
Cited benchmark scores88
Reliability

Provider status

All providers
More matchups

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Public benchmarks are a starting point. Run Claude Fable 5.1 and GPT-5.6 Terra on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.