Prompt to summarize reddit threads

I want to create an efficient workflow to summarize long Reddit threads using LLMs. My current idea is:

1. Save the entire thread as a PDF (using tools like “Save to PDF”).
2. Upload the PDF into ChatGPT or another LLM.
3. Use an optimized prompt to generate a clear, organized, and useful summary.

1. Are there LLMs better than ChatGPT for summarizing long threads?

If anyone has compared models (Claude, Gemini, Perplexity, Llama, Grok, etc.) specifically for long-text summarization, I’d love to hear your experiences.

Thanks in advance!