GPT-4.1 Mini vs Step 3.7 Flash

OpenAI · US  |  StepFun · China · Updated June 2026

Quick verdict

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. Pick Step 3.7 Flash for a 198b-parameter sparse moe vision-language model (11b active) built specifically for agentic coding and search workflows or scmp reported it 'outshines larger rivals' from deepseek and moonshot on some benchmarks despite its smaller active size. Choose Step 3.7 Flash if you need self-hosting or data privacy; GPT-4.1 Mini if you want a managed API.

GPT-4.1 Mini (OpenAI, US) and Step 3.7 Flash (StepFun, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. GPT-4.1 Mini is a cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT. Step 3.7 Flash is stepFun's 198B MoE vision-language model built for coding and search agents - a distinct Chinese lab with genuinely competitive open weights. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGPT-4.1 MiniStep 3.7 Flash
ProviderOpenAI (US) StepFun (China)
ReleasedApril 14, 2025 May 29, 2026
Context window1M (~1,571 pages) 256K (~393 pages)
Price (in/out)$0.4/$1.6 per 1M tokens $0.2/$1.15 per 1M tokens
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, image, code
SWE-Bench Verified23.6% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Very cheap high-volume text work at $0.40 in / $1.60 out per million tokens

GPT-4.1 Mini

Its 1M window holds about 4× more than Step 3.7 Flash's 256K in a single prompt.

Instruction following above its weight class — 84.1% on IFEval, beating GPT-4o

GPT-4.1 Mini

A cheap, fast 1M-context workhorse with strong instruction following but weak coding — already retired from ChatGPT — and it carries the larger 1M context.

Multi-turn coherence for its tier — 35.8% on MultiChallenge, roughly 1.8x GPT-4o mini

GPT-4.1 Mini

GPT-4.1 Mini lists multi-turn coherence for its tier — 35.8% on MultiChallenge, roughly 1.8x GPT-4o mini among its strengths; Step 3.7 Flash does not.

A 198B-parameter sparse MoE vision-language model (11B active) built specifically for agentic coding and search workflows

Step 3.7 Flash

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%

SCMP reported it 'outshines larger rivals' from DeepSeek and Moonshot on some benchmarks despite its smaller active size

Step 3.7 Flash

StepFun's 198B MoE vision-language model built for coding and search agents - a distinct Chinese lab with genuinely competitive open weights — and it runs cheaper at $0.2/$1.15 per 1M tokens.

Open weights (Apache 2.0) at a low per-token price

Step 3.7 Flash

At $0.2/$1.15 per 1M tokens it undercuts GPT-4.1 Mini ($0.4/$1.6 per 1M tokens), and that gap compounds at volume.

Lowest cost at scale

Step 3.7 Flash

At $0.2/$1.15 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

GPT-4.1 Mini

Its 1M window is about 4× larger than Step 3.7 Flash's 256K, fitting roughly 1,571 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Step 3.7 Flash

At $0.2/$1.15 per 1M tokens it undercuts GPT-4.1 Mini, 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.

A team with data-privacy or self-hosting needs

Step 3.7 Flash

Open weights let you run it on your own hardware; GPT-4.1 Mini is API-only.

Anyone whose priority is very cheap high-volume text work at $0.40 in / $1.60 out per million tokens

GPT-4.1 Mini

It is specifically built for that.

Anyone whose priority is a 198b-parameter sparse moe vision-language model (11b active) built specifically for agentic coding and search workflows

Step 3.7 Flash

That is its strongest area.

An enterprise with regional data-residency rules

GPT-4.1 Mini or Step 3.7 Flash

Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.

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 are real: 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.

Step 3.7 Flash: where it fits

StepFun's 198B MoE vision-language model built for coding and search agents - a distinct Chinese lab with genuinely competitive open weights. Released May 29, 2026 by StepFun, it is built for a 198B-parameter sparse MoE vision-language model (11B active) built specifically for agentic coding and search workflows, sCMP reported it 'outshines larger rivals' from DeepSeek and Moonshot on some benchmarks despite its smaller active size, open weights (Apache 2.0) at a low per-token price, and includes a 1.8B vision encoder for image understanding alongside text.

Its trade-offs: stepFun is a newer, less established lab than DeepSeek, Alibaba, or Moonshot, benchmark 'outshines rivals' claims are from press coverage of specific tests, not a full independent leaderboard sweep, and smaller ecosystem and less third-party documentation than the more established Chinese labs. At $0.2 in / $1.15 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

The defining split here is open vs. closed. Step 3.7 Flash gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-4.1 Mini gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both GPT-4.1 Mini and Step 3.7 Flash 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.

See pricing

Frequently asked questions

Is GPT-4.1 Mini or Step 3.7 Flash better for coding?

Public SWE-Bench figures are not available for Step 3.7 Flash, so the honest test is your own repository — run an identical real bug through both. By design, GPT-4.1 Mini leans toward very cheap high-volume text work at $0.40 in / $1.60 out per million tokens while Step 3.7 Flash leans toward a 198b-parameter sparse moe vision-language model (11b active) built specifically for agentic coding and search workflows, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-4.1 Mini or Step 3.7 Flash?

Step 3.7 Flash is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-4.1 Mini is API-metered at $0.4/$1.6 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

GPT-4.1 Mini — 1M vs 256K, about 4× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-4.1 Mini and Step 3.7 Flash together?

Yes — a multi-model platform like LumiChats gives you GPT-4.1 Mini, Step 3.7 Flash 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, GPT-4.1 Mini or Step 3.7 Flash?

Step 3.7 Flash — released May 29, 2026, about 14 months after GPT-4.1 Mini.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.