Where EPS came from
EPS wraps a single-page PostScript program with a bounding box so that page-layout software can place it as artwork. Adobe defined it in 1987 and it dominated print production for two decades. PDF has largely replaced it, but sign makers, stock-image libraries and prepress RIP systems still list EPS as a required deliverable.
The technical picture
Compression: PostScript program text. Transparency: Clipping paths rather than true alpha. Animation: Not supported. Colour: CMYK and spot colours. Typical file size relative to WebP: considerably larger than WebP.
Where it opens
Print and prepress software; no browser renders it. This is usually the deciding factor when choosing between EPS and WebP — WebP renders in every browser but is uneven in desktop software, while EPS has a very different support profile.
Converting EPS to WebP
EPS files are heavy and unviewable outside design software. Converting to WebP produces something you can preview, share and put on a page. The result is a raster image inside a PostScript wrapper, not vector artwork — it will not scale like true vector EPS.
Converting WebP to EPS
Print bureaus, sign manufacturers and prepress pipelines built around PostScript often cannot ingest a .webp at all. EPS wraps the image in the envelope their RIP systems expect. Expect the EPS output to be considerably larger than WebP — that difference is the price of getting a format the destination will actually accept.