GPT-5.3 Chat vs Aion-3.0
Too close to call on our weighted score (GPT-5.3 Chat 28, Aion-3.0 26). The right pick depends on what you value most.
OpenAIGPT-5.3 Chat
28/100- ECI—
- Price$1.75 / $14.00
- Context128K
Aion Labs
Aion-3.0
26/100- ECI—
- Price$3.00 / $6.00
- Context131K
Add a model
Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within 2 points (GPT-5.3 Chat 28/100, Aion-3.0 26/100), so choose by what matters most for your work: Aion-3.0 on price and Aion-3.0 for long inputs. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceAion-3.0Aion-3.0 $3.75 · GPT-5.3 Chat $4.81 per 1M tokens (3:1 blend)
- Longest contextAion-3.0Aion-3.0 131,072 · GPT-5.3 Chat 128,000 tokens
- Widest inputsGPT-5.3 ChatGPT-5.3 Chat: Text, Images · Aion-3.0: Text
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | GPT-5.3 Chat | Aion-3.0 |
|---|---|---|---|
| Price | 50% | 17 | 22 |
| Inputs & features | 30% | 50 | 35 |
| Context window | 20% | 24 | 25 |
| Overall | 100% | 28/100 | 26/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.3 ChatOpenAI | Aion-3.0Aion Labs |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $1.75 (best) | $3.00 |
| Output | $14.00 | $6.00 (best) |
| Cached input | — | — |
| Blended (3:1) | $4.81 | $3.75 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Median of 4 providers | Median of 4 providers |
| Limits | ||
| Context window | 128,000 tokens | 131,072 tokens (best) |
| Max output | 16,384 tokens | 32,768 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | No | Yes |
| Tool calling | Yes | Yes |
| Structured output | No | No |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | — | — |
| API providers | 4 | 4 |
| Released | Mar 3, 2026 | May 5, 2026 |
| Knowledge cutoff | Aug 31, 2025 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.3 Chat$45.50
- Aion-3.0$42.00
Which should you choose?
Which is better: GPT-5.3 Chat or Aion-3.0?
It is close. Our weighted score puts them within 2 points (GPT-5.3 Chat 28/100, Aion-3.0 26/100), so choose by what matters most for your work: Aion-3.0 on price and Aion-3.0 for long inputs. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, GPT-5.3 Chat or Aion-3.0?
Aion-3.0 is cheaper at $3.00 input / $6.00 output per million tokens (median across 4 API providers). GPT-5.3 Chat costs $1.75 input / $14.00 output per million tokens (median across 4 API providers). At a typical mix of three input tokens to one output token, that is $3.75 per million tokens for Aion-3.0 versus $4.81 for GPT-5.3 Chat (1.3× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. GPT-5.3 Chat has not been scored yet and Aion-3.0 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.3 Chat and Aion-3.0 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Aion-3.0 has the largest context window at 131,072 tokens, against 128,000 for GPT-5.3 Chat. Maximum output per response: GPT-5.3 Chat up to 16,384, Aion-3.0 up to 32,768 tokens.
Which can read images, PDFs, audio or video?
GPT-5.3 Chat accepts text and images; Aion-3.0 accepts text. GPT-5.3 Chat handles the widest range of inputs.
Are any of these open source?
No. GPT-5.3 Chat and Aion-3.0 are proprietary and only available through APIs and apps.
Which is newer?
Aion-3.0 is the newest, released May 5, 2026. GPT-5.3 Chat came out Mar 3, 2026. Knowledge cutoff: GPT-5.3 Chat Aug 31, 2025.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
