GPT-5 Nano vs GPT-5.1

At a Glance

Compare
GPT-5.1OpenAI
Intelligence, Cost, and Efficiency
IntelligenceHigher is better · MM Intelligence v2.5#46 of 460.0 score · 2/3 sources · provisional · missing LiveBench · full-core range 0.0–33.3#37 of 4625.7 score · 2/3 sources · provisional · missing LiveBench · full-core range 17.1–50.5
Pricing and Limits
Input priceFrom · USD / 1M tokens$0.025Openrouter · Sep 3, 2026$1.25Openai · Sep 3, 2026
Output priceFrom · USD / 1M tokens$0.20Openrouter · Sep 3, 2026$10.00Openai · Sep 3, 2026
Context windowMaximum documented tokens400K400K
Model facts checkedSep 3, 2026View model evidence →Sep 3, 2026View model evidence →

Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →

Available Benchmarks

All benchmark results →
BenchmarkGPT-5 NanoGPT-5.1
ARC-AGI-1verified-v1-ba05d69f6453 · verified_score · leader20.7128% of row best · percent · GPT-5 Nano (Medium)72.83100% of row best · percent · GPT-5.1 (Thinking, High)
ARC-AGI-2verified-v2-6c676fa3e9af · verified_score · leader2.6115% of row best · percent · GPT-5 Nano (High)17.64100% of row best · percent · GPT-5.1 (Thinking, High)
LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader1,319.7293% of row best · rating · gpt-5-nano-high; 95% CI [1312.87607943, 1326.57003978]; votes 8128; rank 2181,422.57100% of row best · rating · gpt-5.1; 95% CI [1418.95842118, 1426.18777801]; votes 42982; rank 100
LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · leader1,159.1094% of row best · rating · gpt-5-nano-high; 95% CI [1148.05999135, 1170.13906838]; votes 3948; rank 1001,235.08100% of row best · rating · gpt-5.1; 95% CI [1227.35514387, 1242.80648733]; votes 10205; rank 65
ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified61.6281% of row best · points · GPT-5 nano · 7,465 output tokens / case75.98100% of row best · points · GPT-5.1 · 3,970 output tokens / case
Overall ResultCounted from the protocol-matched rows above0 benchmark wins4 benchmark winsOverall lead

Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.

Side-by-Side Facts

FieldGPT-5 NanoGPT-5.1
DeveloperOpenAIOpenAI
FamilyGpt 5Gpt 5 1
ModelGPT-5 NanoGPT-5.1
VersionGPT-5 NanoGPT-5.1
Lifecycleactiveactive
Released2025-08-072025-11-13
Knowledge cutoff2024-05-312024-09-30
Input modalitiesText, ImageText, Image
Output modalitiesTextText
Context window400K400K
Total parametersUnknownUnknown
Active parametersUnknownUnknown
LicenseUnknownUnknown
Open weightsNoNo
API availableYesYes
Self-hostableNoNo
Provider accessOpenai (Standard), Openrouter (Standard)Openai (Standard), Openrouter (Standard)
Capabilitieschat, generation, reasoning, structured_outputs, toolschat, generation, reasoning, structured_outputs, tools

GPT-5 Nano Capabilities

chatgenerationreasoningstructured outputstools
Serving providers2
Canonical IDopenai/gpt-5-nano

GPT-5.1 Capabilities

chatgenerationreasoningstructured outputstools
Serving providers2
Canonical IDopenai/gpt-5.1

Primary Evidence

Sources and Freshness

Questions

GPT-5 Nano vs GPT-5.1 FAQs

Is GPT-5 Nano or GPT-5.1 better for coding?+

This comparison does not currently contain a protocol-matched coding benchmark for both GPT-5 Nano and GPT-5.1, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.

Which is cheaper, GPT-5 Nano or GPT-5.1?+

GPT-5 Nano is $0.025 and GPT-5.1 is $1.25 per million tokens, so GPT-5 Nano is cheaper on this metric. GPT-5 Nano is $0.20 and GPT-5.1 is $10.00 per million tokens, so GPT-5 Nano is cheaper on this metric.

Which has a larger context window, GPT-5 Nano or GPT-5.1?+

Neither model has a larger sourced context window in this comparison. GPT-5 Nano is 400K and GPT-5.1 is 400K.

Which performs better in benchmarks, GPT-5 Nano or GPT-5.1?+

GPT-5.1 leads the current overall benchmark count. The result uses 4 protocol-matched benchmarks from 2 publishers; it is not a universal quality score.

Can GPT-5 Nano or GPT-5.1 be self-hosted?+

Both models have the same recorded self-hosting status: unsupported. GPT-5 Nano is not marked open weight; GPT-5.1 is not marked open weight.

Can GPT-5 Nano and GPT-5.1 understand images?+

GPT-5 Nano is documented with image input; GPT-5.1 is documented with image input. This reflects supported input modalities, not vision quality.

Which can generate longer answers, GPT-5 Nano or GPT-5.1?+

Neither has a larger sourced maximum output. GPT-5 Nano is 128K and GPT-5.1 is 128K.

Do GPT-5 Nano and GPT-5.1 support reasoning and tool use?+

GPT-5 Nano: reasoning, tool calling, and image input. GPT-5.1: reasoning, tool calling, and image input. Feature support does not establish relative quality.

Which is available from more inference providers, GPT-5 Nano or GPT-5.1?+

GPT-5 Nano has 2 sourced provider routes; GPT-5.1 has 2, a tie.

Which offers better value, GPT-5 Nano or GPT-5.1?+

There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.

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