Choose AionLabs: Aion 3.5 if…
- you want the newer model — released 2026-09-23, 18 months after the other
AionLabs: Aion 3.5 vs OpenAI: o4 Mini High
Neither wins outright: AionLabs: Aion 3.5 is the pick when you want the newer model, OpenAI: o4 Mini High when cost matters at scale.
Key numbers
| Spec | AionLabs: Aion 3.5 | OpenAI: o4 Mini High |
|---|---|---|
| Provider | Aion Labs | OpenAI |
| Input price (per 1M tokens) | $3.00 | $1.10 |
| Output price (per 1M tokens) | $6.00 | $4.40 |
| Blended price (3:1 input/output) | $3.75 | $1.93 |
| Cheaper than … of all models we track | 17% | 27% |
| Context window | 262K tokens (~393 pages) | 200K tokens (~300 pages) |
| Larger context than … of all models | 47% | 37% |
| Max output per response | 33K tokens (~24,600 words) | 100K tokens (~75,000 words) |
| Input types | text | image, text, file |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-09-23 | 2025-04-16 |
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What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | AionLabs: Aion 3.5 | OpenAI: o4 Mini High | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $345 | $171 | OpenAI: o4 Mini High saves $175 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $420 | $176 | OpenAI: o4 Mini High saves $244 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $432 | $185 | OpenAI: o4 Mini High saves $247 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $276 | $114 | OpenAI: o4 Mini High saves $162 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $156 | $59.40 | OpenAI: o4 Mini High saves $96.60 |
Capabilities side by side
| Capability | AionLabs: Aion 3.5 | OpenAI: o4 Mini High | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | — | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | — | ✓ Yes | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | ✓ Yes | answer from live web results |
| Seed (reproducible sampling) | — | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- AionLabs: Aion 3.5: price unchanged since we started tracking it on 2026-09-24.
- OpenAI: o4 Mini High: price unchanged since we started tracking it on 2026-03-10.
Which should you choose?
Choose OpenAI: o4 Mini High if…
- cost matters at scale — it is 49% cheaper on a typical 3:1 input/output mix ($171 vs $345 a month for 50,000 support chats)
- you need image input — to read screenshots, charts and scanned pages; AionLabs: Aion 3.5 does not advertise it
- you need file / PDF input — to accept documents without your own parsing step; AionLabs: Aion 3.5 does not advertise it
- you need built-in web search — to answer from live web results; AionLabs: Aion 3.5 does not advertise it
- you need seed (reproducible sampling) — to repeat a generation for tests and evals; AionLabs: Aion 3.5 does not advertise it
- you generate long outputs in one go — up to 100K tokens (about 75,000 words) per response
Frequently asked questions
Is AionLabs: Aion 3.5 better than OpenAI: o4 Mini High?
Neither wins outright: AionLabs: Aion 3.5 is the pick when you want the newer model, OpenAI: o4 Mini High when cost matters at scale. In short: AionLabs: Aion 3.5 when you want the newer model; OpenAI: o4 Mini High when cost matters at scale, you need image input, you need file / PDF input, you need built-in web search, you need seed (reproducible sampling), you generate long outputs in one go.
Which is cheaper, AionLabs: Aion 3.5 or OpenAI: o4 Mini High?
OpenAI: o4 Mini High is cheaper: $1.93 vs $3.75 per 1M tokens at a typical 3:1 input/output mix, 49% less. For 50,000 support conversations a month that is $171 against $345.
How much do AionLabs: Aion 3.5 and OpenAI: o4 Mini High cost per million tokens?
AionLabs: Aion 3.5 costs $3.00 per 1M input tokens and $6.00 per 1M output tokens; OpenAI: o4 Mini High costs $1.10 input and $4.40 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AionLabs: Aion 3.5 or OpenAI: o4 Mini High?
AionLabs: Aion 3.5: 262K tokens, about 393 pages, against 200K (about 300 pages) for OpenAI: o4 Mini High.
Do AionLabs: Aion 3.5 and OpenAI: o4 Mini High support function calling and JSON output?
Tool calling — AionLabs: Aion 3.5: yes, OpenAI: o4 Mini High: yes. JSON-schema structured output — AionLabs: Aion 3.5: yes, OpenAI: o4 Mini High: yes.
Can AionLabs: Aion 3.5 or OpenAI: o4 Mini High read images?
Only OpenAI: o4 Mini High accepts image input; AionLabs: Aion 3.5 is text-only for input.
Is AionLabs: Aion 3.5 or OpenAI: o4 Mini High free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of AionLabs: Aion 3.5 and OpenAI: o4 Mini High?
AionLabs: Aion 3.5 can write up to 33K tokens (about 24,600 words) per response; OpenAI: o4 Mini High up to 100K (about 75,000 words).
When were AionLabs: Aion 3.5 and OpenAI: o4 Mini High released?
AionLabs: Aion 3.5 was listed on 2026-09-23; OpenAI: o4 Mini High on 2025-04-16.
About the two models
AionLabs: Aion 3.5
Aion 3.5 is a multi-model roleplaying and storytelling system from AionLabs, built on the GLM family of models. It uses a collaborative generation process in which multiple specialized models each...
Full AionLabs: Aion 3.5 specs →OpenAI: o4 Mini High
OpenAI o4-mini-high is the same model as [o4-mini](/openai/o4-mini) with reasoning_effort set to high. OpenAI o4-mini is a compact reasoning model in the o-series, optimized for fast, cost-efficient performance while retaining...
Full OpenAI: o4 Mini High specs →