Choose AionLabs: Aion 3.5 if…
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
AionLabs: Aion 3.5 vs Inception: Mercury 2.5 Preview
Inception: Mercury 2.5 Preview comes out ahead on the data we track: 2 advantages and none for AionLabs: Aion 3.5.
Key numbers
| Spec | AionLabs: Aion 3.5 | Inception: Mercury 2.5 Preview |
|---|---|---|
| Provider | Aion Labs | Inception |
| Input price (per 1M tokens) | $3.00 | $0.04 |
| Output price (per 1M tokens) | $6.00 | $0.15 |
| Blended price (3:1 input/output) | $3.75 | $0.07 |
| Cheaper than … of all models we track | 17% | 85% |
| Context window | 262K tokens (~393 pages) | 260K tokens (~390 pages) |
| Larger context than … of all models | 48% | 47% |
| Max output per response | 33K tokens (~24,600 words) | 66K tokens (~49,200 words) |
| Input types | text | text |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-09-23 | 2026-08-31 |
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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 | Inception: Mercury 2.5 Preview | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $345 | $6.00 | Inception: Mercury 2.5 Preview saves $339 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $420 | $6.30 | Inception: Mercury 2.5 Preview saves $414 |
| 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 | $6.60 | Inception: Mercury 2.5 Preview saves $425 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $276 | $4.10 | Inception: Mercury 2.5 Preview saves $272 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $156 | $2.15 | Inception: Mercury 2.5 Preview saves $154 |
Capabilities side by side
| Capability | AionLabs: Aion 3.5 | Inception: Mercury 2.5 Preview | 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 | — | — | 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.
- Inception: Mercury 2.5 Preview: price unchanged since we started tracking it on 2026-09-02.
Which should you choose?
Choose Inception: Mercury 2.5 Preview if…
- cost matters at scale — it is 98% cheaper on a typical 3:1 input/output mix ($6.00 vs $345 a month for 50,000 support chats)
- you generate long outputs in one go — up to 66K tokens (about 49,200 words) per response
Frequently asked questions
Is AionLabs: Aion 3.5 better than Inception: Mercury 2.5 Preview?
Inception: Mercury 2.5 Preview comes out ahead on the data we track: 2 advantages and none for AionLabs: Aion 3.5.
Which is cheaper, AionLabs: Aion 3.5 or Inception: Mercury 2.5 Preview?
Inception: Mercury 2.5 Preview is cheaper: $0.07 vs $3.75 per 1M tokens at a typical 3:1 input/output mix, 98% less. For 50,000 support conversations a month that is $6.00 against $345.
How much do AionLabs: Aion 3.5 and Inception: Mercury 2.5 Preview cost per million tokens?
AionLabs: Aion 3.5 costs $3.00 per 1M input tokens and $6.00 per 1M output tokens; Inception: Mercury 2.5 Preview costs $0.04 input and $0.15 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AionLabs: Aion 3.5 or Inception: Mercury 2.5 Preview?
AionLabs: Aion 3.5: 262K tokens, about 393 pages, against 260K (about 390 pages) for Inception: Mercury 2.5 Preview.
Do AionLabs: Aion 3.5 and Inception: Mercury 2.5 Preview support function calling and JSON output?
Tool calling — AionLabs: Aion 3.5: yes, Inception: Mercury 2.5 Preview: yes. JSON-schema structured output — AionLabs: Aion 3.5: yes, Inception: Mercury 2.5 Preview: yes.
Can AionLabs: Aion 3.5 or Inception: Mercury 2.5 Preview read images?
Neither accepts image input — both are text-in models.
Is AionLabs: Aion 3.5 or Inception: Mercury 2.5 Preview 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 Inception: Mercury 2.5 Preview?
AionLabs: Aion 3.5 can write up to 33K tokens (about 24,600 words) per response; Inception: Mercury 2.5 Preview up to 66K (about 49,200 words).
When were AionLabs: Aion 3.5 and Inception: Mercury 2.5 Preview released?
AionLabs: Aion 3.5 was listed on 2026-09-23; Inception: Mercury 2.5 Preview on 2026-08-31.
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 →Inception: Mercury 2.5 Preview
Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception. Instead of generating tokens sequentially, Mercury 2.5 produces and refines multiple tokens in parallel, achieving...
Full Inception: Mercury 2.5 Preview specs →