How I Use all the Top-Tier AI Models Without Spending a Cent
I use AI heavily for coding. Editors or IDE with AI being integrated usually provide an Agent mode. It is the "I do whatever I think is necessary with your code base"-mode. The AI creates, modifies, deletes files and directories and executes commands on the command line. It literally works as if a human programmer would be coding for me.
When I use AI to crank out code in big amounts–and also use the best models that exist at that time–then the bill starts to get expensive quickly. In 4 days I consume my €20 budget which normally would last 1 month. Huuu, not cheap! Wouldn't it be cool if I could use the best models at a fraction or at no cost at all. Sounds too good to be true!
By accident I stumbled across an article about prompting and a list of sites which provide a generous free-tier of the best models. Here's the list I curated and I sorted it from often to hardly used:
- LMArena: Claude Opus/Sonnet, GPT-5 High and more
- z.ai's GLM 4.5
- Kimi K2
- Qwen3 Coder
- Deepseek
- Grok
- Google Gemini AI Studio
- Google Gemini 2.5 Pro: similar to AI Studio but with better image generation and deep search
- Poe
- OpenRouter: some models are free others not
- ChatGPT: free version is good
- Perplexity
There's a catch though: I pay it with little convenience compared to using the AIs in the IDE. I need to jump around between tabs, include code from files in the prompts myself. For composing prompts I use this tool. I select the files I want to include, write what I want AI to do and it will put the content of all files plus my instruction into the clipboard. Then I copy it into the chat window of one these AI services mentioned above. The prompt looks similar to this:
### START OF FILE css/style.css ###
@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&display=swap');
@import "tailwindcss";
@theme {
--default-font-family: 'Inter', var(--font-sans);
}
@layer components {
.btn-secondary {
@apply px-6 py-3;
}
}
### END OF FILE css/style.css ###
Add a red primary-action button style!
It's not more complicated than that. I started to develop an intuition for which model works well for a certain type of task.