# OpenAI vs Baseten

> OpenAI's closed models against Baseten's fast, OpenAI-compatible open-model endpoints. One sells GPT; the other sells low first-token latency and a place to run your own model.

Canonical: https://www.subconscious.dev/compare/openai-vs-baseten · By The Subconscious Team · Updated September 30, 2026

## How they compare

Baseten's Model APIs speak the OpenAI Chat Completions shape, so code written for OpenAI can point at Baseten with a base URL change and reach open models like GLM 5.2, DeepSeek V4, Kimi K3 or gpt-oss 120B. That makes the comparison practical rather than theoretical. OpenAI brings GPT-6 Astra and the GPT-5.6 tiers, a 1.05M window and hosted tools. Baseten brings the lowest time to first token on the Artificial Analysis provider board in August 2026, 0.49 seconds, and KV cache-aware routing that pays off on agentic coding traffic.

The deployment options pull further apart. OpenAI is an API, reachable direct or through Azure OpenAI and Bedrock. Baseten adds dedicated deployments of any model packaged with Truss, per-minute GPU billing with scale to zero, self-hosting, HIPAA and data residency options, and a 99.99% uptime SLA. Its limit is a 13-model catalog, and anything off-list means running your own deployment, with an H100 at about $6.50 an hour. For the strongest closed model, OpenAI is the pick. For a private fine-tune or a custom speech model, Baseten fits better.

## What each one does

### OpenAI

OpenAI runs the most widely adopted closed-model API. Its September 2026 lineup has GPT-6 Astra at the top for computer use, coding and long agentic runs, priced at $10 in and $50 out per million tokens. Below it sits the GPT-5.6 family: Sol for hard professional work, Terra as the balanced default, and Luna for high-volume jobs at $0.20 in and $1.20 out. All of them carry a 1.05M token context window with up to 128K output.

### Baseten

Baseten runs two products. Model APIs serve a curated set of 13 open models, including DeepSeek V4, GLM 5.2, Kimi K3 and gpt-oss 120B, over endpoints that speak both the OpenAI Chat Completions shape and the Anthropic Messages shape. That dual compatibility means an existing OpenAI or Claude SDK, or a coding agent, points at Baseten with a base URL change. Dedicated deployments take any model you package with the open-source Truss CLI and bill per GPU minute, with an H100 at about $6.50 an hour.

## Which is best, and when

### Choose OpenAI for

- Frontier closed models with no infrastructure work
- Browser and desktop automation agents
- High-volume jobs on Luna with Batch discounts

### Choose Baseten for

- Latency-critical apps that need the fastest first token
- Serving private fine-tunes or custom speech and embedding models
- Regulated buyers needing self-host or data residency

## At a glance

| Attribute | OpenAI | Baseten |
|---|---|---|
| Model access | Closed, plus open gpt-oss | Open weights, 13 curated |
| Flagship models | GPT-6 Astra, GPT-5.6 Sol, Terra, Luna | GLM 5.2, DeepSeek V4, Kimi K3, gpt-oss 120B |
| Speed | Fast mode: up to 2.5x at 2x price | 0.49s TTFT, lowest measured |
| Price | $0.20–$10 in, $1.20–$50 out per 1M | H100 about $6.50/hr dedicated |
| Customization | N/A | Deploy any model with Truss |
| Deployment | API, Azure OpenAI, Bedrock | Model APIs, dedicated, self-host |
| Long context | 1.05M; 2x input past 272K | Varies by model |

## FAQ

### What is the difference between OpenAI and Baseten?

OpenAI's closed models against Baseten's fast, OpenAI-compatible open-model endpoints. One sells GPT; the other sells low first-token latency and a place to run your own model.

### When should I choose OpenAI over Baseten?

Frontier closed models with no infrastructure work; Browser and desktop automation agents; High-volume jobs on Luna with Batch discounts.

### When should I choose Baseten over OpenAI?

Latency-critical apps that need the fastest first token; Serving private fine-tunes or custom speech and embedding models; Regulated buyers needing self-host or data residency.

### Is OpenAI or Baseten cheaper?

OpenAI: $0.20–$10 in, $1.20–$50 out per 1M. Baseten: H100 about $6.50/hr dedicated. The cheaper choice depends on the model and workload.

### Which has more context, OpenAI or Baseten?

OpenAI: 1.05M; 2x input past 272K. Baseten: Varies by model.

## Running long-horizon agents?

If your agents run past 200K tokens, compare both against Subconscious: [Subconscious vs OpenAI](https://www.subconscious.dev/compare/subconscious-vs-openai.md), [Subconscious vs Baseten](https://www.subconscious.dev/compare/subconscious-vs-baseten.md).

Full profiles: [OpenAI](https://www.subconscious.dev/providers/openai.md), [Baseten](https://www.subconscious.dev/providers/baseten.md).