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 Mini
OpenAI: GPT-4 Turbo
Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$80.50
$1,350
AionLabs: Aion 3.5 Mini saves $1,270
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$98.00
$1,500
AionLabs: Aion 3.5 Mini saves $1,402
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)
$101
$1,560
AionLabs: Aion 3.5 Mini saves $1,459
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$64.40
$980
AionLabs: Aion 3.5 Mini saves $916
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$36.40
$530
AionLabs: Aion 3.5 Mini saves $494
Capabilities side by side
Capability
AionLabs: Aion 3.5 Mini
OpenAI: GPT-4 Turbo
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)
—
✓ Yes
repeat a generation for tests and evals
Log-probabilities
—
✓ Yes
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 Mini: price unchanged since we started tracking it on 2026-09-24.
OpenAI: GPT-4 Turbo: price unchanged since we started tracking it on 2026-03-10.
Which should you choose?
Choose AionLabs: Aion 3.5 Mini if…
cost matters at scale — it is 94% cheaper on a typical 3:1 input/output mix ($80.50 vs $1,350 a month for 50,000 support chats)
you need to fit long inputs in one request — 262K tokens is roughly 393 pages, against 192
you need reasoning / thinking mode — to spend extra tokens thinking before answering hard problems; OpenAI: GPT-4 Turbo does not advertise it
you generate long outputs in one go — up to 33K tokens (about 24,600 words) per response
you want the newer model — released 2026-09-23, 30 months after the other
Choose OpenAI: GPT-4 Turbo if…
you need image input — to read screenshots, charts and scanned pages; AionLabs: Aion 3.5 Mini does not advertise it
you need seed (reproducible sampling) — to repeat a generation for tests and evals; AionLabs: Aion 3.5 Mini does not advertise it
you need log-probabilities — to read token confidence for classification and scoring; AionLabs: Aion 3.5 Mini does not advertise it
Frequently asked questions
Is AionLabs: Aion 3.5 Mini better than OpenAI: GPT-4 Turbo?
Neither wins outright: AionLabs: Aion 3.5 Mini is the pick when cost matters at scale, OpenAI: GPT-4 Turbo when you need image input. In short: AionLabs: Aion 3.5 Mini when cost matters at scale, you need to fit long inputs in one request, you need reasoning / thinking mode, you generate long outputs in one go, you want the newer model; OpenAI: GPT-4 Turbo when you need image input, you need seed (reproducible sampling), you need log-probabilities.
Which is cheaper, AionLabs: Aion 3.5 Mini or OpenAI: GPT-4 Turbo?
AionLabs: Aion 3.5 Mini is cheaper: $0.87 vs $15.00 per 1M tokens at a typical 3:1 input/output mix, 94% less. For 50,000 support conversations a month that is $80.50 against $1,350.
How much do AionLabs: Aion 3.5 Mini and OpenAI: GPT-4 Turbo cost per million tokens?
AionLabs: Aion 3.5 Mini costs $0.70 per 1M input tokens and $1.40 per 1M output tokens; OpenAI: GPT-4 Turbo costs $10.00 input and $30.00 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AionLabs: Aion 3.5 Mini or OpenAI: GPT-4 Turbo?
AionLabs: Aion 3.5 Mini: 262K tokens, about 393 pages, against 128K (about 192 pages) for OpenAI: GPT-4 Turbo.
Do AionLabs: Aion 3.5 Mini and OpenAI: GPT-4 Turbo support function calling and JSON output?
Aion 3.5 Mini is a multi-model roleplaying and storytelling system from AionLabs, built on the GLM family of models. It is the smaller, lower-cost sibling of Aion 3.5 and uses...