GPT-5 mini vs GPT-5 nano

GPT-5 mini (OpenAI, 272,000-token context) versus GPT-5 nano (OpenAI, 272,000-token context). GPT-5 nano is cheaper by 80% on a blended token mix. Across 3 public benchmarks we tracked, GPT-5 mini wins 3 and GPT-5 nano wins 0. Use the live calculator below to plug your real usage shape into both, then route the winner via Agent Command Center for shadow A/B without code changes.

Bottom line — GPT-5 mini vs GPT-5 nano

GPT-5 mini and GPT-5 nano target overlapping workloads but differ sharply on economics. GPT-5 nano runs roughly 80% cheaper on a blended input-plus-output token mix, which translates to approximately $1,560 per month at mid-market volume (100K requests/day). The gap compounds at enterprise scale, making the cost axis the first filter most teams apply when deciding between these two models.

Across 3 public benchmarks, GPT-5 mini leads on 3 and GPT-5 nano leads on 0. The widest gap is on arena-elo, where GPT-5 mini scores 70.0 points higher. Benchmarks are noisy and task-dependent — a model that leads on arena-elo may trail on code generation. The safest approach is to run both models on your own golden set before treating any benchmark as decisive.

For teams evaluating both models, the recommended path is a shadow A/B test: route production traffic through an OpenAI-compatible gateway, mirror a percentage to the candidate model, score both responses with an automated evaluator (faithfulness, tool-call correctness, latency), and compare cohort-level metrics over two weeks. Future AGI Agent Command Center supports this pattern with a single `base_url` change and built-in evaluators from the ai-evaluation SDK.

Side-by-side cost

Live workload comparison

Same workload run through both models. The cheaper one is highlighted.

3,000
0272,000
400
0128,000
5,000
01,000,000
OpenAI
$236/mo
Input $0.250/M · Output $2.00/M
GPT-5 nanoCheaper
OpenAI
$47.18/mo
Input $0.0500/M · Output $0.400/M
At this workload, GPT-5 nano is 80% cheaper than GPT-5 mini — a savings of $189/month ($2,265/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
  model: gpt-5-nano
  provider: openai
fallback:
  model: gpt-5-mini
  provider: openai
shadow: { sample_rate: 0.05 }   # mirror 5% of traffic to compare quality live
GPT-5 mini GPT-5 nano
Input price $0.250/M $0.0500/M
Output price $2.00/M $0.400/M
Context window 272,000 272,000
Max output 128,000 128,000
Function calling
Vision
Audio input
Reasoning
Prompt caching
Structured output
Pricing verified Jun 2, 2026 Jun 2, 2026
Cheaper option
~80% cheaper than the priciest in this pair
Larger context
272,000 tokens
More capabilities
5 of 6 capability flags advertised

Benchmark comparison

Side-by-side public benchmark scores. Greener bar = winner.

Chatbot Arena ELOgeneral
GPT-5 mini
1,395
GPT-5 nano
1,325
HumanEvalcode
GPT-5 mini
93.5%
GPT-5 nano
86.3%
AIME 2024math
GPT-5 mini
91.1%
GPT-5 nano
MMLU-Proreasoning
GPT-5 mini
82.0%
GPT-5 nano
73.0%
GPQA Diamondreasoning
GPT-5 mini
78.4%
GPT-5 nano
SWE-bench Verifiedagent
GPT-5 mini
68.0%
GPT-5 nano

Cost at scale: monthly spend at three usage volumes

Estimated monthly cost assuming 1,000 input + 200 output tokens per request — a realistic chat-agent shape. Adjust your own usage in the calculator at the top of this page for an exact number.

Scale GPT-5 mini GPT-5 nano Delta
Startup
10K requests/day
$195 /mo $39.00 /mo $156/mo
Mid-market
100K requests/day
$1,950 /mo $390 /mo $1,560/mo
Enterprise
1M requests/day
$19,500 /mo $3,900 /mo $15,600/mo

At enterprise scale (1M requests/day), a difference of even ~10% in unit price compounds into thousands of dollars per month. Cached input pricing and batch tiers can shift this further — both are surfaced on each model's own page.

When to choose which

Picked from the data above — not vendor marketing. Match the rules to your workload, not the other way around.

Choose GPT-5 nano

You're cost-sensitive at scale — GPT-5 nano runs ~80% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume.

Choose GPT-5 mini

On arena-elo, GPT-5 mini scores 70.0 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.

Benchmark winners — by the numbers

For each public benchmark that has scores for both models, the higher score and the size of the gap. Benchmarks are noisy — treat anything under a 2-point delta as effectively tied.

Benchmark GPT-5 mini GPT-5 nano Winner Δ
arena-elo 1395.0 1325.0 GPT-5 mini +70.0
humaneval 93.5 86.3 GPT-5 mini +7.2
mmlu-pro 82.0 73.0 GPT-5 mini +9.0

How to A/B test GPT-5 mini vs GPT-5 nano in production

If you're stuck between the two, run them side-by-side on real traffic. Four steps the Future AGI team uses internally:

  1. 1. Point your existing OpenAI SDK at https://gateway.futureagi.com/v1. No code change beyond base_url and a virtual key.
  2. 2. Mark GPT-5 mini primary, mirror 20% of traffic to GPT-5 nano in shadow mode. Both responses are logged; only the primary is served to users.
  3. 3. Score every shadow response with an evaluator — faithfulness, tool-call correctness, response latency, cost. Built-in evaluators in ai-evaluation cover the common axes.
  4. 4. Compare cohort-level metrics after two weeks. Switch primary when the candidate wins on what matters to your workload — and stays within your latency budget.

Full walkthrough on the Agent Command Center page.

FAQ — GPT-5 mini vs GPT-5 nano

Which is cheaper, GPT-5 mini or GPT-5 nano?

GPT-5 nano is cheaper by roughly 80% on a blended input + output token mix. Input prices are $0.250/M for GPT-5 mini versus $0.0500/M for GPT-5 nano; output prices are $2.00/M versus $0.400/M. The exact savings depend on your input:output ratio — use the live calculator above to plug in your own request shape.

What is the context window of GPT-5 mini versus GPT-5 nano?

GPT-5 mini supports up to 272,000 tokens of context. GPT-5 nano supports up to 272,000 tokens. GPT-5 nano has the larger window by a factor of 1.0x, which matters for long-document RAG, multi-turn agent sessions, and tasks that need to keep an entire codebase in working memory.

Do GPT-5 mini and GPT-5 nano both support tool calling?

Yes — both GPT-5 mini and GPT-5 nano support native function calling. Both also support structured output via JSON schema, so an agent can be ported between them with the same tool definitions.

Which model supports prompt caching for cost reduction?

Both GPT-5 mini and GPT-5 nano support prompt caching. Cached input tokens are typically discounted 50–90% versus uncached input, depending on the provider. For agents with a stable system prompt + retrieval context, the cached pricing tier is the real unit economics number to track.

When should I choose GPT-5 mini over GPT-5 nano?

On arena-elo, GPT-5 mini scores 70.0 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.

When should I choose GPT-5 nano over GPT-5 mini?

You're cost-sensitive at scale — GPT-5 nano runs ~80% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume.

How do I A/B test GPT-5 mini against GPT-5 nano in production?

Route both through an OpenAI-compatible gateway like Future AGI Agent Command Center with shadow mode enabled. Send 100% of traffic to your primary model, mirror 10–20% to the candidate, score every response with an evaluator (faithfulness, tool-call correctness, response time), and compare cohort-level metrics for two weeks. Switch when the candidate wins on the metrics that matter to your workload and stays within your latency budget.