Pick Claude Fable 5.1 for terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%) or cursorbench 3.2 agentic coding (73.4%). Pick GPT-4.1 Mini for very cheap high-volume text work at $0.40 in / $1.60 out per million tokens or instruction following above its weight class — 84.1% on ifeval, beating gpt-4o. On a tight budget at scale, GPT-4.1 Mini is the value pick.
Claude Fable 5.1 (Anthropic) and GPT-4.1 Mini (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Fable 5.1 is anthropic's September 1, 2026 update to its Fable line for coding and knowledge work, keeping the 1M-token context of Fable 5 while cutting cache-read costs and roughly doubling agentic-research benchmark scores. GPT-4.1 Mini is a cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
Price: GPT-4.1 Mini is about 25× cheaper on input ($0.4/$1.6 per 1M tokens vs $10/$50 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
Context window: 1M tokens vs 1M — within a few percent of each other, so treat this as a tie and test on your own long inputs, since usable recall varies by model.
Recency: Claude Fable 5.1 is the newer model by about 17 months (released September 1, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
Claude Fable 5.1
GPT-4.1 Mini
Provider
Anthropic (US)
OpenAI (US)
Released
September 1, 2026
April 14, 2025
Context window
1M tokens (~1,500 pages)
1M (~1,571 pages)
Price (in/out)
$10/$50 per 1M tokens
$0.4/$1.6 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image
text, image, code
SWE-Bench Verified
Not published
23.6%
MRCR v2 @ 1M
Not published
Not published
Who wins what
Terminal-Bench-Science agentic research (52.6%, more than double Fable 5's 24.7%): Claude Fable 5.1 — GPT-4.1 Mini is comparatively weak here — weak at agentic coding — its 23.6% on SWE-Bench Verified sits below GPT-4o's 33.2%
CursorBench 3.2 agentic coding (73.4%): Claude Fable 5.1 — Anthropic's September 1, 2026 update to its Fable line for coding and knowledge work, keeping the 1M-token context of Fable 5 while cutting cache-read costs and roughly doubling agentic-research benchmark scores — and it is the newer of the two.
Cache-read pricing cut to a quarter of other Claude models: Claude Fable 5.1 — Claude Fable 5.1 lists cache-read pricing cut to a quarter of other Claude models among its strengths; GPT-4.1 Mini does not.
Very cheap high-volume text work at $0.40 in / $1.60 out per million tokens: GPT-4.1 Mini — At $0.4/$1.6 per 1M tokens it undercuts Claude Fable 5.1 ($10/$50 per 1M tokens), and that gap compounds at volume.
Instruction following above its weight class — 84.1% on IFEval, beating GPT-4o: GPT-4.1 Mini — Claude Fable 5.1 is comparatively weak here — closed weights, no self-hosting option
Multi-turn coherence for its tier — 35.8% on MultiChallenge, roughly 1.8x GPT-4o mini: GPT-4.1 Mini — A cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT — and it runs cheaper at $0.4/$1.6 per 1M tokens.
Lowest cost at scale: GPT-4.1 Mini — At $0.4/$1.6 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume: GPT-4.1 Mini — At $0.4/$1.6 per 1M tokens it undercuts Claude Fable 5.1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: GPT-4.1 Mini — Larger 1M window fits more in one prompt.
Anyone whose priority is terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%): Claude Fable 5.1 — It is specifically built for that.
Anyone whose priority is very cheap high-volume text work at $0.40 in / $1.60 out per million tokens: GPT-4.1 Mini — That is its strongest area.
Claude Fable 5.1: where it fits
Anthropic's September 1, 2026 update to its Fable line for coding and knowledge work, keeping the 1M-token context of Fable 5 while cutting cache-read costs and roughly doubling agentic-research benchmark scores. Released September 1, 2026 by Anthropic, it is built for terminal-Bench-Science agentic research (52.6%, more than double Fable 5's 24.7%), cursorBench 3.2 agentic coding (73.4%), cache-read pricing cut to a quarter of other Claude models, and long, multistep, document-heavy professional work with 1M-token context.
Its trade-offs are real: anthropic has not published an official SWE-bench Verified score for this model, restricted Mythos 5.1 variant outscores it on some benchmarks due to lighter safeguards (Terminal-Bench 4.0: 60.9% vs 55.8%), and closed weights, no self-hosting option. At $10 in / $50 out per million tokens, it sits in the premium price band.
GPT-4.1 Mini: where it fits
A cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT. Released April 14, 2025 by OpenAI, it is built for very cheap high-volume text work at $0.40 in / $1.60 out per million tokens, instruction following above its weight class — 84.1% on IFEval, beating GPT-4o, multi-turn coherence for its tier — 35.8% on MultiChallenge, roughly 1.8x GPT-4o mini, and a full 1M context at flat pricing, with no long-context premium.
Its trade-offs: weak at agentic coding — its 23.6% on SWE-Bench Verified sits below GPT-4o's 33.2%, retired from ChatGPT in February 2026, and OpenAI's own docs now point users to GPT-5 mini instead, and a June 2024 knowledge cutoff, now roughly two years stale, and no reasoning mode. At $0.4 in / $1.6 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Claude Fable 5.1 and GPT-4.1 Mini overlap enough that the right pick depends on your specific job. GPT-4.1 Mini costs less per token; GPT-4.1 Mini holds the larger context; and each leads in its own area — Claude Fable 5.1 for terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%), GPT-4.1 Mini for very cheap high-volume text work at $0.40 in / $1.60 out per million tokens. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is Claude Fable 5.1 or GPT-4.1 Mini better for coding?
Public SWE-Bench figures are not available for Claude Fable 5.1, so the honest test is your own repository — run an identical real bug through both. By design, Claude Fable 5.1 leans toward terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%) while GPT-4.1 Mini leans toward very cheap high-volume text work at $0.40 in / $1.60 out per million tokens, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Fable 5.1 or GPT-4.1 Mini?
GPT-4.1 Mini is cheaper — $10/$50 per 1M tokens vs $0.4/$1.6 per 1M tokens, roughly 25× apart on input.
Which has the bigger context window?
Effectively neither — 1M tokens vs 1M is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Claude Fable 5.1 and GPT-4.1 Mini together?
Yes — a multi-model platform like LumiChats gives you Claude Fable 5.1, GPT-4.1 Mini and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Fable 5.1 or GPT-4.1 Mini?
Claude Fable 5.1 — released September 1, 2026, about 17 months after GPT-4.1 Mini.
Claude Fable 5.1 vs GPT-4.1 Mini
Anthropic · US | OpenAI · US · Updated June 2026
Quick verdict
Pick Claude Fable 5.1 for terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%) or cursorbench 3.2 agentic coding (73.4%). Pick GPT-4.1 Mini for very cheap high-volume text work at $0.40 in / $1.60 out per million tokens or instruction following above its weight class — 84.1% on ifeval, beating gpt-4o. On a tight budget at scale, GPT-4.1 Mini is the value pick.
Claude Fable 5.1 (Anthropic) and GPT-4.1 Mini (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Fable 5.1 is anthropic's September 1, 2026 update to its Fable line for coding and knowledge work, keeping the 1M-token context of Fable 5 while cutting cache-read costs and roughly doubling agentic-research benchmark scores. GPT-4.1 Mini is a cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
▸Price: GPT-4.1 Mini is about 25× cheaper on input ($0.4/$1.6 per 1M tokens vs $10/$50 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
▸Context window: 1M tokens vs 1M — within a few percent of each other, so treat this as a tie and test on your own long inputs, since usable recall varies by model.
▸Recency: Claude Fable 5.1 is the newer model by about 17 months (released September 1, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Claude Fable 5.1
GPT-4.1 Mini
Provider
Anthropic (US)
OpenAI (US)
Released
September 1, 2026
April 14, 2025
Context window
1M tokens (~1,500 pages)
1M (~1,571 pages)
Price (in/out)
$10/$50 per 1M tokens
$0.4/$1.6 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image
text, image, code
SWE-Bench Verified
Not published
23.6%
MRCR v2 @ 1M
Not published
Not published
Who wins what
Terminal-Bench-Science agentic research (52.6%, more than double Fable 5's 24.7%)
Claude Fable 5.1
GPT-4.1 Mini is comparatively weak here — weak at agentic coding — its 23.6% on SWE-Bench Verified sits below GPT-4o's 33.2%
CursorBench 3.2 agentic coding (73.4%)
Claude Fable 5.1
Anthropic's September 1, 2026 update to its Fable line for coding and knowledge work, keeping the 1M-token context of Fable 5 while cutting cache-read costs and roughly doubling agentic-research benchmark scores — and it is the newer of the two.
Cache-read pricing cut to a quarter of other Claude models
Claude Fable 5.1
Claude Fable 5.1 lists cache-read pricing cut to a quarter of other Claude models among its strengths; GPT-4.1 Mini does not.
Very cheap high-volume text work at $0.40 in / $1.60 out per million tokens
GPT-4.1 Mini
At $0.4/$1.6 per 1M tokens it undercuts Claude Fable 5.1 ($10/$50 per 1M tokens), and that gap compounds at volume.
Instruction following above its weight class — 84.1% on IFEval, beating GPT-4o
GPT-4.1 Mini
Claude Fable 5.1 is comparatively weak here — closed weights, no self-hosting option
Multi-turn coherence for its tier — 35.8% on MultiChallenge, roughly 1.8x GPT-4o mini
GPT-4.1 Mini
A cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT — and it runs cheaper at $0.4/$1.6 per 1M tokens.
Lowest cost at scale
GPT-4.1 Mini
At $0.4/$1.6 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ GPT-4.1 Mini
At $0.4/$1.6 per 1M tokens it undercuts Claude Fable 5.1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ GPT-4.1 Mini
Larger 1M window fits more in one prompt.
Anyone whose priority is terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%)
→ Claude Fable 5.1
It is specifically built for that.
Anyone whose priority is very cheap high-volume text work at $0.40 in / $1.60 out per million tokens
→ GPT-4.1 Mini
That is its strongest area.
Claude Fable 5.1: where it fits
Anthropic's September 1, 2026 update to its Fable line for coding and knowledge work, keeping the 1M-token context of Fable 5 while cutting cache-read costs and roughly doubling agentic-research benchmark scores. Released September 1, 2026 by Anthropic, it is built for terminal-Bench-Science agentic research (52.6%, more than double Fable 5's 24.7%), cursorBench 3.2 agentic coding (73.4%), cache-read pricing cut to a quarter of other Claude models, and long, multistep, document-heavy professional work with 1M-token context.
Its trade-offs are real: anthropic has not published an official SWE-bench Verified score for this model, restricted Mythos 5.1 variant outscores it on some benchmarks due to lighter safeguards (Terminal-Bench 4.0: 60.9% vs 55.8%), and closed weights, no self-hosting option. At $10 in / $50 out per million tokens, it sits in the premium price band.
GPT-4.1 Mini: where it fits
A cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT. Released April 14, 2025 by OpenAI, it is built for very cheap high-volume text work at $0.40 in / $1.60 out per million tokens, instruction following above its weight class — 84.1% on IFEval, beating GPT-4o, multi-turn coherence for its tier — 35.8% on MultiChallenge, roughly 1.8x GPT-4o mini, and a full 1M context at flat pricing, with no long-context premium.
Its trade-offs: weak at agentic coding — its 23.6% on SWE-Bench Verified sits below GPT-4o's 33.2%, retired from ChatGPT in February 2026, and OpenAI's own docs now point users to GPT-5 mini instead, and a June 2024 knowledge cutoff, now roughly two years stale, and no reasoning mode. At $0.4 in / $1.6 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Claude Fable 5.1 and GPT-4.1 Mini overlap enough that the right pick depends on your specific job. GPT-4.1 Mini costs less per token; GPT-4.1 Mini holds the larger context; and each leads in its own area — Claude Fable 5.1 for terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%), GPT-4.1 Mini for very cheap high-volume text work at $0.40 in / $1.60 out per million tokens. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Claude Fable 5.1 and GPT-4.1 Mini without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
Is Claude Fable 5.1 or GPT-4.1 Mini better for coding?
Public SWE-Bench figures are not available for Claude Fable 5.1, so the honest test is your own repository — run an identical real bug through both. By design, Claude Fable 5.1 leans toward terminal-bench-science agentic research (52.6%, more than double fable 5's 24.7%) while GPT-4.1 Mini leans toward very cheap high-volume text work at $0.40 in / $1.60 out per million tokens, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Fable 5.1 or GPT-4.1 Mini?
GPT-4.1 Mini is cheaper — $10/$50 per 1M tokens vs $0.4/$1.6 per 1M tokens, roughly 25× apart on input.
Which has the bigger context window?
Effectively neither — 1M tokens vs 1M is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Claude Fable 5.1 and GPT-4.1 Mini together?
Yes — a multi-model platform like LumiChats gives you Claude Fable 5.1, GPT-4.1 Mini and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Fable 5.1 or GPT-4.1 Mini?
Claude Fable 5.1 — released September 1, 2026, about 17 months after GPT-4.1 Mini.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.