DEV Community: Theo Slater

I Built a Desktop Chat App for Running Local LLMs Offline

Theo Slater — Wed, 20 May 2026 15:16:48 +0000

A few months ago I got tired of bouncing between ChatGPT, Claude, and a dozen other AI chat UIs every time I wanted to test a different model. It felt like productivity, if productivity involved tab overload and constant context switching.

I also wanted to run everything locally without sending data off to someone else’s server just to ask a question about JSON formatting.

So I built Openbench AI.

What it is

OpenBench is a desktop chat app that connects to Ollama and lets you talk to local LLMs without the usual ritual of Docker, Python environments, or “why is this port not working again” debugging sessions.

You install it. You open it. You chat.

That’s it.

Key features

Multi-model chat (side by side comparison)

You can run multiple models at once and watch them respond in real time to the same prompt.

Instead of guessing which model is best, you can just compare them directly under identical conditions like a mildly scientific experiment that occasionally exposes how inconsistent models can be.

Markdown + LaTeX support

Full rendering via KaTeX.

So when a model writes equations or structured explanations, it actually looks like something a human might willingly read.

Guest mode

Temporary chats that disappear when you close the app.

No storage. No accounts. No memory overhead.

Just quick experiments without commitment.

Ollama model management

You can install models directly inside the app instead of juggling terminal commands and hoping you typed everything correctly the first time.

Conversation tools

Archive chats
System prompt presets
CUstom system prompt
Clean interface without unnecessary clutter.

Tech stack

Tauri
Zustand
MUI
SQLite
ollama-rs

What i would change

If I rebuilt it, I’d add OpenAI-compatible API support from day one.

Right now it only works with Ollama, though the architecture already supports additional providers. I just haven’t wired them in yet because priorities are a fictional concept.

Open source

The project is open source, and release builds are available if you want to try it without compiling anything yourself.

Openbench GitHub

Closing note

Somewhere between building multi-model streaming and debugging Rust event bridges, I learned that the world did not strictly need another chat UI.

So I made one anyway.

For what it’s worth, it behaves better than most tools that have significantly more funding and optimism.

And yes, it works just fine for a gay developer trying to wrangle multiple AI models without losing their mind to tool fragmentation.

Which is probably more honesty than most software documentation is legally allowed to contain.