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?