I'm looking for short stories or novelettes of about 20-50 pages

I love a novella. I didn’t look up page counts but here’s some I remember being shorter and worth reading

• Bartleby the Scrivener by Herman Melville
• Ethan Frome by Edith Wharton
• Notes from Underground by Fyodor Dosktoevsky
• The Death of Ivan Illych by Lev Tolstoy
• The House on Mango Street by Sandra Cisneros
• The Island of Doctor Moreau by H.G. Wells
• The Overcoat by Nikolai Gogol
• The Nose by Nikolai Gogol
• The Pearl by John Steinbeck

https://libraryofshortstories.com/

Harlan Ellison has good scifi horror ones. I have no mouth and I must scream and other good ones

By the Waters of Babylon may be my favorite short story I've read.

Turn of the Screw - Henry James

I assume other genres probably have them, but for scifi there’s a lot anthologies that cover short stories. I like them that the stories can be read in a session, sometimes multiple. One of the shortest I’ve seen is Isaac Asimovs postcard story, fits ona postcard!

Scifi that was the only way to get published way back when, scifi was seen as too risky for long form printing.

In scifi, it’s even goes further into themes so you can pick what you like. Examples would be ghost stories, or time travel, detectives, space ships only. Stuff like that.

Some free options.

Sorted by "Shorts' then length.

https://standardebooks.org/subjects/shorts?sort=length

The Quiet Boy, it's free online, unfortunately can't remember the author. Lovely and spooky

Welcome to the Monkey House by Kurt Vonnegut. Its 25 short stories on 352 pages though, so on average 14 pages.

Ray Bradbury is my absolute favourite short story writer.

Plays are also good options. I loved the Crucible by Arthur Miller when I read it earlier this year.

If you like weird then check out Richard Braugtigan

"The Yellow Wallpaper" is like 25 pages and pretty good I've heard. Its on my Xmas list.

I love this by Hillary Mantel. Her book of short stories (The Assassination of Margaret Thatcher) I also thought was good.

Cuentos de amor de locura y de muerte