AionLabs: Aion-1.0 vs XingChen: Xing4.0 29B A4B (free)

XingChen: Xing4.0 29B A4B (free) comes out ahead on the data we track: 8 advantages and none for AionLabs: Aion-1.0.

Key numbers

SpecAionLabs: Aion-1.0XingChen: Xing4.0 29B A4B (free)
ProviderAion LabsXingchen Agi
Input price (per 1M tokens)$4.00$0
Output price (per 1M tokens)$8.00$0
Blended price (3:1 input/output)$5.00$0
Cheaper than … of all models we track10%90%
Context window131K tokens (~197 pages)262K tokens (~393 pages)
Larger context than … of all models23%48%
Max output per response33K tokens (~24,600 words)236K tokens (~176,900 words)
Input typestexttext
Output typestexttext
Free variantNoYes
Listed since2025-02-042026-10-16

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-1.0XingChen: Xing4.0 29B A4B (free)Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$460$0XingChen: Xing4.0 29B A4B (free) saves $460
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$560$0XingChen: Xing4.0 29B A4B (free) saves $560
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)
$576$0XingChen: Xing4.0 29B A4B (free) saves $576
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$368$0XingChen: Xing4.0 29B A4B (free) saves $368
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$208$0XingChen: Xing4.0 29B A4B (free) saves $208

Capabilities side by side

CapabilityAionLabs: Aion-1.0XingChen: Xing4.0 29B A4B (free)What it lets you do
Tool / function calling—✓ Yescall your APIs and run agent loops
Structured output (JSON schema)—✓ Yesreturn JSON that validates against your schema
Reasoning / thinking mode✓ Yes✓ Yesspend 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)—✓ Yesrepeat 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

Which should you choose?

Choose AionLabs: Aion-1.0 if…

No advantage on the data we track — pick it for provider preference or output quality on your own prompts.

Choose XingChen: Xing4.0 29B A4B (free) if…

  • cost matters at scale — it is 100% cheaper on a typical 3:1 input/output mix ($0 vs $460 a month for 50,000 support chats)
  • you need to fit long inputs in one request — 262K tokens is roughly 393 pages, against 197
  • you need tool / function calling — to call your APIs and run agent loops; AionLabs: Aion-1.0 does not advertise it
  • you need structured output (JSON schema) — to return JSON that validates against your schema; AionLabs: Aion-1.0 does not advertise it
  • you need seed (reproducible sampling) — to repeat a generation for tests and evals; AionLabs: Aion-1.0 does not advertise it
  • you generate long outputs in one go — up to 236K tokens (about 176,900 words) per response
  • you want to prototype at zero cost — a free variant is listed
  • you want the newer model — released 2026-10-16, 21 months after the other

Frequently asked questions

Is AionLabs: Aion-1.0 better than XingChen: Xing4.0 29B A4B (free)?

XingChen: Xing4.0 29B A4B (free) comes out ahead on the data we track: 8 advantages and none for AionLabs: Aion-1.0.

Which is cheaper, AionLabs: Aion-1.0 or XingChen: Xing4.0 29B A4B (free)?

XingChen: Xing4.0 29B A4B (free) is cheaper: $0 vs $5.00 per 1M tokens at a typical 3:1 input/output mix, 100% less. For 50,000 support conversations a month that is $0 against $460.

How much do AionLabs: Aion-1.0 and XingChen: Xing4.0 29B A4B (free) cost per million tokens?

AionLabs: Aion-1.0 costs $4.00 per 1M input tokens and $8.00 per 1M output tokens; XingChen: Xing4.0 29B A4B (free) costs $0 input and $0 output. Output tokens are billed separately, so long answers shift the gap.

Which has the bigger context window, AionLabs: Aion-1.0 or XingChen: Xing4.0 29B A4B (free)?

XingChen: Xing4.0 29B A4B (free): 262K tokens, about 393 pages, against 131K (about 197 pages) for AionLabs: Aion-1.0.

Do AionLabs: Aion-1.0 and XingChen: Xing4.0 29B A4B (free) support function calling and JSON output?

Tool calling — AionLabs: Aion-1.0: not advertised, XingChen: Xing4.0 29B A4B (free): yes. JSON-schema structured output — AionLabs: Aion-1.0: not advertised, XingChen: Xing4.0 29B A4B (free): yes.

Can AionLabs: Aion-1.0 or XingChen: Xing4.0 29B A4B (free) read images?

Neither accepts image input — both are text-in models.

Is AionLabs: Aion-1.0 or XingChen: Xing4.0 29B A4B (free) free to use?

XingChen: Xing4.0 29B A4B (free) has a free variant (xingchen-agi/xing4.0-29b-a4b:free). Free variants usually carry tighter rate limits.

What is the maximum output length of AionLabs: Aion-1.0 and XingChen: Xing4.0 29B A4B (free)?

AionLabs: Aion-1.0 can write up to 33K tokens (about 24,600 words) per response; XingChen: Xing4.0 29B A4B (free) up to 236K (about 176,900 words).

When were AionLabs: Aion-1.0 and XingChen: Xing4.0 29B A4B (free) released?

AionLabs: Aion-1.0 was listed on 2025-02-04; XingChen: Xing4.0 29B A4B (free) on 2026-10-16.

About the two models

Aion Labs

AionLabs: Aion-1.0

Aion-1.0 is a multi-model system designed for high performance across various tasks, including reasoning and coding. It is built on DeepSeek-R1, augmented with additional models and techniques such as Tree of Thoughts (ToT) and Mixture of Experts (MoE). It is Aion Lab's most powerful reasoning model.

Full AionLabs: Aion-1.0 specs →

Compare AionLabs: Aion-1.0 with other models

Compare XingChen: Xing4.0 29B A4B (free) with other models

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