I've tried both the drag and drop (which displayed the image as a new page, leaving the "make a post" page behind) and "attach files" method (which said the image was not expected type, though it was jpeg or jpg).
Maximum file size: Set to 50,240 KB (≈49–50 MB) per attachment.
Maximum image dimensions: 3840 × 2160 (4K). Images exceeding the bounds may be resampled or rejected.
Practical tips
Drag-and-drop into the editor works and hosts the file on HardForum’s servers.
Compress large photos (e.g., export as JPEG at 80–90% quality) and keep dimensions reasonable so pages load quickly for everyone.
If an upload is rejected, resize/compress and try again, or fall back to an external host (Imgur, etc.) and use an image tag.
The attachment manager in a post will list accepted files and their sizes.
We simply cannot account for every browser, every browser config, every available browser plugin, etc., etc., etc. The HardForum has ZERO business model. Our admin is payed for by members here through subscription purchases and Patreon legacy members (which provide most of the money spent keeping our infrastructure running). We do what we can. Bottom line, I still pay for keeping this running out of my pocket every month and there are going to be some things that could certainly be more polished.