Choose AionLabs: Aion 3.5 if…
- you need reasoning / thinking mode — to spend extra tokens thinking before answering hard problems; Pareto 26.9 does not advertise it
AionLabs: Aion 3.5 vs Pareto 26.9
Neither wins outright: AionLabs: Aion 3.5 is the pick when you need reasoning / thinking mode, Pareto 26.9 when you need image input.
Key numbers
| Spec | AionLabs: Aion 3.5 | Pareto 26.9 |
|---|---|---|
| Provider | Aion Labs | Unbiased |
| Input price (per 1M tokens) | $3.00 | $2.50 |
| Output price (per 1M tokens) | $6.00 | $7.50 |
| Blended price (3:1 input/output) | $3.75 | $3.75 |
| Cheaper than … of all models we track | 17% | 17% |
| Context window | 262K tokens (~393 pages) | 262K tokens (~393 pages) |
| Larger context than … of all models | 48% | 48% |
| Max output per response | 33K tokens (~24,600 words) | 131K tokens (~98,300 words) |
| Input types | text | text, image |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-09-23 | 2026-10-13 |
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 | Pareto 26.9 | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $345 | $338 | Pareto 26.9 saves $7.50 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $420 | $375 | Pareto 26.9 saves $45.00 |
| 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 | $390 | Pareto 26.9 saves $42.00 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $276 | $245 | Pareto 26.9 saves $31.00 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $156 | $133 | Pareto 26.9 saves $23.50 |
Capabilities side by side
| Capability | AionLabs: Aion 3.5 | Pareto 26.9 | 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 | — | 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 | — | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | — | answer from live web results |
| Seed (reproducible sampling) | — | — | 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.
- Pareto 26.9: price unchanged since we started tracking it on 2026-10-14.
Which should you choose?
Choose Pareto 26.9 if…
- you need image input — to read screenshots, charts and scanned pages; AionLabs: Aion 3.5 does not advertise it
- you generate long outputs in one go — up to 131K tokens (about 98,300 words) per response
Frequently asked questions
Is AionLabs: Aion 3.5 better than Pareto 26.9?
Neither wins outright: AionLabs: Aion 3.5 is the pick when you need reasoning / thinking mode, Pareto 26.9 when you need image input. In short: AionLabs: Aion 3.5 when you need reasoning / thinking mode; Pareto 26.9 when you need image input, you generate long outputs in one go.
Which is cheaper, AionLabs: Aion 3.5 or Pareto 26.9?
They cost the same: $3.75 per 1M tokens at a 3:1 input/output mix.
How much do AionLabs: Aion 3.5 and Pareto 26.9 cost per million tokens?
AionLabs: Aion 3.5 costs $3.00 per 1M input tokens and $6.00 per 1M output tokens; Pareto 26.9 costs $2.50 input and $7.50 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AionLabs: Aion 3.5 or Pareto 26.9?
Both take 262K tokens per request — roughly 393 pages of text.
Do AionLabs: Aion 3.5 and Pareto 26.9 support function calling and JSON output?
Tool calling — AionLabs: Aion 3.5: yes, Pareto 26.9: yes. JSON-schema structured output — AionLabs: Aion 3.5: yes, Pareto 26.9: yes.
Can AionLabs: Aion 3.5 or Pareto 26.9 read images?
Only Pareto 26.9 accepts image input; AionLabs: Aion 3.5 is text-only for input.
Is AionLabs: Aion 3.5 or Pareto 26.9 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 Pareto 26.9?
AionLabs: Aion 3.5 can write up to 33K tokens (about 24,600 words) per response; Pareto 26.9 up to 131K (about 98,300 words).
When were AionLabs: Aion 3.5 and Pareto 26.9 released?
AionLabs: Aion 3.5 was listed on 2026-09-23; Pareto 26.9 on 2026-10-13.
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 →Pareto 26.9
Pareto is a multimodal composite model built for research, coding, and agentic workflows, while delivering frontier-level performance across a broad range of general-purpose tasks.
Full Pareto 26.9 specs →