For example, I know that sites like duck.ai let you use LLMs for free, but they limit input to 16,000 characters, so you can’t actually leverage models like Llama 4 Scout, which supposedly has a 10 million token context window. Are there any platforms or tools (preferably without a paywall or input cap) where I could use models with context windows in the millions, as advertised? Or are all the free tools similarly restricted by much smaller limits?
Unfortunately, you’re probably not gonna find one.
The size of the context window is almost the only thing that matter re: cost to run these agents, so you’ll never get a large one for free.
You could always self host something like lm studio and download some models of interest and adjust to the highest amount of input. Of course you will be limited by the hardware as well as the model. As an example, I don’t think LM Studio imposes a limit, it depends on the model.
My apologies if I misunderstood any of your question.
LM Studio is free
Openrouter provides some limited free usage of popular LLMs with context sizes up to 175k etc. This is probably as good as you’ll get for completely free. The prices are usually pretty reasonable per million tokens as well if you don’t mind paying a bit. https://openrouter.ai/
Edit: looks like there’s a Gemini Pro free option with million plus token context size as well.
Gemini Cli