Finding free guest posting sites can be a bit challenging since many platforms now prefer curated and quality content. However, there are still some places where you might be able to contribute guest posts without fees. Here are some methods to find them:

1. Google Search: Use search queries like “write for us” + [your niche], “guest post” + [your niche], or “submit a guest post” + [your niche]. This can yield blogs or websites that accept guest contributions.
2. Social Media: Look for groups or communities on platforms like Facebook, LinkedIn, or Reddit where bloggers or website owners share opportunities for guest posting.
3. Directories and Lists: Some websites curate lists of blogs or websites that accept guest posts. While not all might be free, you can find some options that don’t charge.
4. Check Niche-Specific Websites: Explore websites related to your niche. Some might openly invite guest posts or have a “write for us” page where they provide guidelines for submissions.
5. Networking: Engage with other bloggers, writers, or website owners in your niche. Sometimes, through networking, you might discover opportunities for guest posting.

Remember, even if a site offers free guest posting, they often have guidelines and quality standards for submissions. Always ensure your content is well-written, relevant, and adds value to the platform’s audience.