Setup Guide · Tested March 2026

Best AI Model for Open WebUI (2026 Setup Guide)

Open WebUI is a self-hosted ChatGPT alternative that supports OpenAI-compatible APIs. This guide shows how to connect it to CheapAI's proxy so you can access Claude, Gemini, and DeepSeek models at up to 65% below direct pricing — without changing your Open WebUI setup.

Tested in Open WebUI by CheapAI team ~5 min read March 2026

Testing Methodology & Trade-offs

How we test: We actively maintain an Open WebUI test instance connected to the CheapAI proxy. We periodically verify that streaming works securely, function calling successfully parses, and that multi-modal image inputs route correctly to Claude and Gemini endpoints.

Trade-offs: Open WebUI was built natively around Official OpenAI endpoints. While most features work seamlessly through our OpenAI compatibility layer, very specific edge-case experimental features in Open WebUI that aren't adopted in standard OpenAI libraries may encounter minor UI visual bugs.

How to Connect CheapAI to Open WebUI

Get a CheapAI API key

Purchase a plan at CheapAI pricing. You'll receive an API key and proxy base URL within 24 hours.

Open WebUI Admin Panel

Add OpenAI connection

Under OpenAI API, click the + icon to add a new connection and enter:

URL:
https://cheapai-netifly-app.up.railway.app/v1
Key:
YOUR_CHEAPAI_API_KEY

Save and refresh available models

Click Save. Open WebUI will call /v1/models to fetch the available model list. CheapAI returns all available model IDs from this endpoint.

Select a model and start chatting

From the model dropdown in the chat UI, select your preferred CheapAI model. Recommended starting points:

Best all-rounder

claude-sonnet-4-6-20260217

Fastest / cheapest

deepseek-chat

Most capable

claude-opus-4-6-20260205

Multimodal

gemini-3.1-pro-preview

Test Evidence

CheapAI team tested chat completions via Open WebUI's OpenAI connection type in March 2026.
Model: claude-sonnet-4-6-20260217 via https://cheapai-netifly-app.up.railway.app/v1
Streaming mode confirmed working. Multi-turn conversations confirmed working.
Image upload / vision input: not yet tested via Open WebUI (depends on Open WebUI's image handling).
Open WebUI version tested: latest stable as of March 2026. See compatibility matrix for the full log.

Common Questions

Can I use multiple CheapAI models at once?

Yes. Open WebUI will fetch all model IDs from /v1/models and list them in the dropdown. You can switch between Claude, GPT, Gemini, and DeepSeek within the same Open WebUI instance.

Do I need a self-hosted Open WebUI instance?

Yes, this guide assumes you are running your own Open WebUI instance (Docker or otherwise). The Admin → Connections panel is only available to instance admins.

Is streaming supported?

Yes. Our proxy supports Server-Sent Events (SSE) streaming. Open WebUI's streaming mode was tested successfully in March 2026 with Claude Sonnet 4.6.

Ready to power your Open WebUI?

Get a CheapAI key and access Claude Sonnet 4.6, Gemini, DeepSeek, and more at up to 65% off.

Get Access →