So here's a list I compiled of SFF venues that publish their content for free online! I made it for my students. Maybe they will be bored and will click around in the Discussions section of Blackboard that I have created for them.
I've arranged them alphabetically, with some notes at the end, and if you want to help me flesh out the notes, you are welcome to do so!
Abyss & Apex:
http://www.abyssapexzine.com/Acidic Fiction:
http://acidicfiction.com/AE Scifi:
http://aescifi.ca/index.php/fiction (CANADIA!)
Anathema Magazine:
http://www.anathemamag.com/Andromeda Spaceways:
http://www.andromedaspaceways.com/ (selected fiction from past issues)
AntipodeanSF:
http://www.antisf.com/ (SF from Down Under! Australia and NZ)
Apex Magazine:
http://www.apex-magazine.com/ Aphelion Webzine:
http://www.aphelion-webzine.com/index.htmlArsenika:
http://arsenika.ink/ (speculative poetry and flash fiction)
Augur Magazine:
http://www.augurmag.comBeneath Ceaseless Skies:
http://www.beneath-ceaseless-skies.com/ (specializing in high fantasy)
Betwixt Magazine:
http://betwixtmagazine.com/Bewildering Stories:
http://www.bewilderingstories.com/Big Echo Critical SF:
http://www.bigecho.org/Black Girl Magic Mag:
http://www.blackgirlmagicmag.com/Blind Spot:
http://blindspot.pub/ (translations of French science fiction into English)
Body Parts Magazine:
http://www.bodypartsmagazine.com (horror and erotica)
Bourbon Penn:
http://www.bourbonpenn.com/ (slipstream, surreal, magical realism)
Buzzy Mag:
http://buzzymag.com/ (SF, urban fantasy, epic fantasy, horror)
Cafe Irreal:
http://cafeirreal.alicewhittenburg.com/ (fantastic fiction)
Capricious:
http://www.capricioussf.org/ (aims to feature at least one New Zealand writer per issue)
Cast of Wonders:
http://www.castofwonders.org/category/episodes/ (YA fiction podcast)
Cheapjack Pulp:
http://www.cheapjackpulp.com/ (not everything is speculative; everything is pulpy, as it says on the tin)
Chrome Baby:
http://robindunn.com/chrome-baby-index.htmlClarkesworld Magazine:
http://clarkesworldmagazine.com/ The Colored Lens:
http://thecoloredlens.com/Common Oddities Speculative Fiction Sideshow:
http://www.commonodditiessideshow.com/index.htmlCompelling Science Fiction:
http://compellingsciencefiction.com/index.htmlCosmos Magazine:
https://cosmosmagazine.com/fictionCrossed Genres:
http://crossedgenres.com/magazine/ (ceasing publication Dec 2015 ;_; )
Daily Science Fiction:
http://dailysciencefiction.com/The Dark Magazine:
http://thedarkmagazine.com/ Delinquent's Spice:
http://www.delinquentspice.com/ (hypertext fiction)
Devilfish Review:
http://devilfishreview.com/Diabolical Plots:
http://www.diabolicalplots.com/tag/fiction-2/ (once a month)
Dreamforge Magazine:
https://dreamforge.mywebportal.app/dreamforge/browse/fiction/allElectric Velocipede:
http://www.electricvelocipede.com/ (it has sadly ceased publication but most of the work is still available for free reading)
EscapePod:
http://escapepod.org/ (podcast)
Every Day Fiction:
http://www.everydayfiction.com/ (flash fiction)
Expanded Horizons:
http://expandedhorizons.net/magazine/Eye to the Telescope:
http://eyetothetelescope.com/index.html (SFPA online journal of spec po)
Fantasist Mag:
http://thefantasistmag.com/ (fantasy novellas)
Fantastic Stories of the Imagination:
http://www.fantasticstoriesoftheimagination.com/ (mostly flash fic, <3000 word stories)
Fantasy Magazine:
http://www.fantasy-magazine.com/Fantasy Scroll:
http://fantasyscrollmag.com/Far Fetched Fables:
http://farfetchedfables.com/ (reprint podcast)
Farrago's Wainscot:
http://www.farragoswainscot.com/ (Weird fiction and poetry)
Farther Stars Than These:
http://www.fartherstars.com/ (SF flash)
Fever Dreams:
http://fdezine.fever-dreams.co.uk/ (PDF download)
Fiction Vortex:
http://www.fictionvortex.com/Fiyah Lit Magazine:
http://www.fiyahlitmag.com/ (lit journal of black SF)
Flapperhouse:
http://flapperhouse.com/zine/ (not specifically SF, but "lit that’s surreal, shadowy, sensual, and/or satirical")
Flash Fiction Online:
http://flashfictiononline.com/main/ (not strictly SF; its tag has a range of spec fic and other genres)
The Future Fire:
http://futurefire.net/GigaNotoSaurus:
http://giganotosaurus.org/ (for longish fiction)
Gingerbread House Lit Mag:
http://gingerbreadhouselitmag.com/ (literary magic)
GlitterShip:
http://www.glittership.com/ (LGBTQ SFF podcast)
Goblin Fruit:
http://www.goblinfruit.net/ (fantastical poetry)
The Golden Key:
http://www.whatwonderfulthings.net/main/ (speculative and literary journal inspired by the Grimm Brothers' fairytale of the same name)
Grey Matter:
https://meiziuspublishing.wordpress.com/grey-matter-a-science-fiction-fantasy-digest/ (PDF download)
The Grievous Angel:
http://www.urbanfantasist.com/latest-sci-fi--fantasy-poetry--flash-fictionHeliotrope Mag:
http://www.heliotropemag.com/ (PDF download)
Hello Horror:
http://www.hellohorror.com/Heroic Fantasy Quarterly:
http://www.heroicfantasyquarterly.com/Hogglepot:
http://hogglepot.com/Ideomancer:
http://www.ideomancer.com/Imaginary Beasts:
http://imaginarybeasts.livejournal.com/Indian SF:
https://indiansf.wordpress.com/Inkscrawl:
http://inkscrawl.net/ (minimalist fantastical poetry)
Inscription Magazine:
http://www.inscriptionmagazine.com/fiction/ (SFF for teens)
Interfictions:
http://interfictions.com/ (journal of "interstitial" art; generally unclassifiable SF)
International SF:
https://internationalsf.wordpress.com/short-stories/InterNova:
http://nova-sf.de/internova/ (international SF)
Journal of Compressed Creative Arts:
http://matterpress.com/journal/Kaleidotrope:
http://www.kaleidotrope.net/Kasma Magazine:
http://www.kasmamagazine.com/index.cfmLackington's Magazine:
http://lackingtons.com/Lakeside Circus:
http://lakesidecircus.com/Lamplight Magazine:
http://lamplightmagazine.com/ (literary dark fiction)
Ligature Works:
http://www.ligatureworks.com/ (poetry and fiction)
Lightspeed Magazine:
http://www.lightspeedmagazine.com/Liminality:
http://www.liminalitypoetry.com/ (speculative poetry)
Liquid Imagination:
http://liquidimagination.silverpen.org/Lorelei Signal:
http://www.loreleisignal.com/LoreleiSignal.htmlLovecraft eZine:
http://lovecraftzine.com/magazine/issues/ Luna Station Quarterly:
http://lunastationquarterly.com/Mad Scientist Journal:
http://madscientistjournal.org/Mantid Magazine:
https://www.mantidmagazine.com/ (women in genre)
Metaphorosis:
http://magazine.metaphorosis.com/Middle Planet:
http://middle-planet.com/Mirror Dance Fantasy:
http://www.mirrordancefantasy.com/Mithila Review:
http://mithilareview.com/Mothership Zeta:
http://mothershipzeta.org/ Mystic Nebula:
http://mysticnebula.com/Mythic Delirium:
http://mythicdelirium.com/ (started as a speculative poetry magazine, now also publishes fiction)
New Myths:
https://sites.google.com/a/newmyths.com/nmwebsite/homeNightmare Magazine:
http://www.nightmare-magazine.com/ (horror & dark fantasy)
Omenana Magazine:
http://omenana.com/ (SFF from African and African diaspora writers)
Perihelion:
http://www.perihelionsf.com/Phantasmacore:
http://www.phantasmacore.com/Phantom Kangaroo:
http://phantomkangaroo.com/ (speculative poetry)
Planet Magazine:
http://www.planetmag.com/Plasma Frequency:
http://www.plasmafrequencymagazine.com/Plunge:
http://www.plungemagazine.com/ (queer women in genre)
Podcastle (audio stories):
http://podcastle.org/Pseudopod (audio stories):
http://pseudopod.org/ (horror)
Scigentasy:
http://www.scigentasy.com/category/fiction/ (dedicated to issues of gender in speculative fiction)
See The Elephant:
http://www.metaphysicalcircus.com/category/swag-free-short-fiction/ (selected fiction)
Shimmer:
http://www.shimmerzine.com/Silver Blade:
http://www2.silverblade.net/Solarpunk Press:
http://www.solarpunkpress.com/Sorcerous Signals:
http://www.sorceroussignals.com/SorcerousSignals.htmlSQ Mag:
http://sqmag.com/Stone Telling:
http://stonetelling.com/ (speculative poetry)
Strange Constellations:
http://www.strangeconstellations.com/Strange Horizons:
http://www.strangehorizons.com/Strangelet Journal:
http://www.strangeletjournal.com/Sub-saharan Magazine:
http://subsaharanmagazine.com/ (Nigerian-based African SF magazine)
sub-Q Magazine:
https://sub-q.com/ (interactive fiction)
Subterranean Press Magazine:
http://subterraneanpress.com/magazineTerraform:
http://motherboard.vice.com/terraformTheme of Absence:
http://www.themeofabsence.com/story-archive/ (flashfic and short shorts, 1000 - 3000 words)
Three-Lobed Burning Eye:
http://www.3lobedmag.com/Through The Gate:
http://throughthegate.net/ (fantastical poetry)
Tiger Shark:
http://tigersharkpublishing.blogspot.com/ (PDF download)
Tor.com Online:
http://www.tor.com/stories/prose Twisted Moon Magazine:
http://twistedmoonmag.com/index.html (speculative erotic poetry)
Uncanny Magazine:
http://uncannymagazine.com/Unlikely Story:
http://www.unlikely-story.com/Unsung Stories:
http://www.unsungstories.co.uk/short/Urban Fantasy Magazine:
http://urbanfantasymagazine.com/Usok:
http://www.rocketkapre.com/usok/ (Rocket Kapre's zine of Filipino fiction, currently on hiatus after the second issue)
Weird Fiction Review:
http://weirdfictionreview.com/category/fiction/ (what it says on the tin)
The Wi Files:
http://thewifiles.com/If there are more I don't have (and I feel there's one more I saw but I just don't remember what /o\) drop it in comments, too.
ETA: Updated June 22, thanks @offvesta!!
ETA: Updated Nov 12, using SFPA market listing.
ETA: Updated April 14, yoinked off Vajra's bib