Here are the top 3 alternatives to ImageUpload.net for hosting and sharing images, focusing on similar features (free, no account required, direct links):

1.ImgBB (imgbb.com)

• Why it is 1: Very reliable, fast, and offers similar direct image links (BBCode, HTML, Markdown). No account needed for uploads up to 32MB. It also preserves image quality better than many competitors.

2.Imgur (imgur.com)

• Why it is 2: Extremely popular and stable. While designed as a community platform, you can upload anonymously and get direct image URLs. Great for high traffic. Just be aware they may remove inactive images after ~6 months for anonymous uploads.

3.PostImage (postimages.org)

• Why it is 3: Very simple interface, no account required, and supports large files (up to 10MB anonymously, more with free account). Offers multiple link types including "hotlink for forums." One of the oldest free image hosts still running.

Close runner-up: FreeImage.host  if you need longer file retention (they claim permanent for registered users) and a modern interface similar to ImageUpload.net.

Important note for any alternative: Always review their Terms of Service regarding prohibited content (e.g., adult, copyrighted, illegal material) and image retention periods for anonymous uploads, as many free hosts delete inactive images after a set time (e.g., 30 days to 6 months).