JPG, TXT, Word documents, Excel spreadsheets, PDFs, just to name a few.
When you upload documents, audio files, or images under the Attachments section, some file types can be previewed using the preview tool (the eye icon). A lightbox will appear, allowing you to view the content without downloading it.
Here are the supported preview file types:
Images
png, jpeg, jpg
Documents
txt, xls, xlsx, doc, docx, pdf, rtf
Audio/Video
mp3, wav, ogg
Note: You can still upload other file types (see the full list here), but those may need to be downloaded to view their contents.