Why compare models at all
With 410 models available from 9 providers, choosing one for each task can feel like guesswork. Models differ in real, practical ways: how much text they can take in one go, whether they can read images, how quickly they answer, and how deeply they reason.
JustSimpleChat gives you two honest ways to decide. The models directory shows every model's specifications, straight from the registry the app runs on. And because every model lives in the same chat interface, you can put the same prompt to two or three of them and compare the actual answers rather than the marketing.
We deliberately do not publish our own benchmark scores or speed ratings. Benchmarks age quickly and rarely match your specific work. Your own prompts, run side by side, are a better test than any leaderboard.
What you can compare
Context windows
How much text a model can process in one request. The current catalogue tops out at 2,000,000 tokens. Compare windows against your typical documents so nothing gets truncated mid-task.
Capabilities
Which models support vision, tool use, extended reasoning and other features. The directory lists each model's capabilities so you never discover a missing feature mid-task.
Speed class
Models are grouped by how they trade speed against depth, from the fastest lightweight models to deep reasoning ones. Pick fast models for drafts and iterations, deeper ones for final work.
Real answers
The comparison that matters most: run your actual prompt on different models in chat and judge the responses directly. Style, accuracy and format differences show up immediately.
Example: current lead models compared
| Specification | GPT-6 Astra | Claude Fable 5.1 | Gemini 3.8 Flash |
|---|---|---|---|
| Provider | OpenAI | Anthropic | |
| Context window | 1,050,000 tokens | 1,000,000 tokens | 1,048,576 tokens |
| Capabilities | reasoning, vision, multimodal, analysis, function_calling, structured_output, web_search, code_interpreter, hosted_shell, apply_patch, skills, computer_use, mcp, tool_search, code_generation, thinking_mode, long_context, research, agentic_workflows | reasoning, vision, function_calling, structured_output, extended_thinking, multimodal, analysis, code_generation, code_execution, tool_use, long_context, agentic_workflows | reasoning, vision, function_calling, structured_output, multimodal, analysis, fast_response, long_context, tool_use, code_generation, thinking_mode, agentic_workflows, audio_processing |
| Speed class | deep | deep | fast |
Specifications are read from the live model registry at render time, so this table always matches what you can actually use in chat.
Getting started with model comparison
Browse the directory
Visit the models directory to see every model with its provider, context window and capabilities in one table.
Shortlist for your task
Narrow down by what your work needs: a large context window for long documents, vision for images, or a fast model for quick iterations.
Test with real prompts
Open chat and put the same prompt to your shortlisted models. Compare the answers on quality, style and format, then keep the model that suits your work best.
Frequently asked questions
How do I compare models in JustSimpleChat?↓
Two ways. The models directory lists all 410 models with their provider, context window and capabilities, so you can compare specifications at a glance. In chat, you can run the same prompt against different models side by side and compare the actual answers.
Where does the comparison data come from?↓
From the model registry the app itself runs on. The specifications shown on the models page are the same ones used to route your chats, so what you compare is always what you can actually use.
What specifications can I compare?↓
Provider, context window (how much text a model can take in one request), capabilities such as vision or tool use, and relative speed. Anything a provider has not published is simply not shown; we do not fill gaps with estimates.
Why does context window matter?↓
Context window is the maximum amount of text a model can process in one request, measured in tokens. Bigger windows let you work with long documents and codebases without chopping them up. The largest context window in the current catalogue is 2,000,000 tokens.
Does comparing models cost extra?↓
No. Each prompt you send counts as one message on your plan, whichever model answers. Testing a prompt on three models uses three messages, and nothing more.
How current is the comparison data?↓
The pages are generated from the live registry, so when models are added, retired or updated, the comparison reflects it. There is no separately maintained spec sheet that can drift out of date.
Can I test models with my own prompts?↓
Yes, and it is the comparison we recommend most. Ask the same question to two or three models in chat and judge the answers on your own work. Specifications tell you what a model can take; your own prompts tell you which one you prefer.