Free Online Co-Op Games on Steam
Steam currently has 6,387 Online Co-Op games available to download and play. Explore our list of the best free games ranked by popularity and ratings. Data for this list is calculated from reviews and player counts reported directly by Steam and will be updated in real-time. Free Online Co-Op game rankings were last updated on 1/15/2025.
Looking for more? Explore other lists such as:
- Best online co-op games on Steam
- Best online co-op Steam Deck games
- Best online co-op Steam games for Mac OS
- Best online co-op Linux games on Steam
- Free Steam games
- Most played Steam games
- Best rated Steam games
1. Counter-Strike 2
For over two decades, Counter-Strike has offered an elite competitive experience, one shaped by millions of players from across the globe. And now the next chapter in the CS story is about to begin. This is Counter-Strike 2.
Counter-Strike 2 holds the #1 spot for "best free Online Co-Op game on Steam" with a Player Score of 87. Its score was calculated by analyzing a total of 8,486,558 reviews on Steam. This breaks down to a total of 7,373,310 positive reviews and 1,113,248 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is possible to play Counter-Strike 2 on the Steam Deck (though some functionality may be limited).
2. Marvel Rivals
Marvel Rivals is a Super Hero Team-Based PVP Shooter! Assemble an all-star Marvel squad, devise countless strategies by combining powers to form unique Team-Up skills and fight in destructible, ever-changing battlefields across the continually evolving Marvel universe!
Marvel Rivals has achieved a Player Score of 80, placing it in the #2 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 159,806 reviews on Steam. This breaks down to a total of 129,997 positive reviews and 29,809 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Marvel Rivals on the Steam Deck (though some functionality may be limited).
| Release Date | 12/6/2024 |
| Developer | NetEase Games |
| Publisher | NetEase Games |
| Steam App Id | 2767030 |
3. Dota 2
Every day, millions of players worldwide enter battle as one of over a hundred Dota heroes. And no matter if it's their 10th hour of play or 1,000th, there's always something new to discover. With regular updates that ensure a constant evolution of gameplay, features, and heroes, Dota 2 has taken on a life of its own.
Dota 2 has achieved a Player Score of 81, placing it in the #3 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 2,413,108 reviews on Steam. This breaks down to a total of 1,969,273 positive reviews and 443,835 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play Dota 2 on the Steam Deck (though some functionality may be limited).
4. Warframe
Awaken as an unstoppable warrior and battle alongside your friends in this story-driven free-to-play online action game
Warframe has achieved a Player Score of 87, placing it in the #4 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 605,290 reviews on Steam. This breaks down to a total of 529,148 positive reviews and 76,142 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. Valve has also verified it as playable on the Steam Deck and will run well.
| Release Date | 3/25/2013 |
| Developer | Digital Extremes |
| Publisher | Digital Extremes |
| Steam App Id | 230410 |
5. Delta Force
Delta Force, a free-to-play 1st-person tactical shooter, returns as the latest in the classic series. With 25 years defining the genre, Delta Force is back with an upgraded arsenal of weaponry, jaw-dropping environments, and a truly dynamic world.
Delta Force has achieved a Player Score of 70, placing it in the #5 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 61,649 reviews on Steam. This breaks down to a total of 43,627 positive reviews and 18,022 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Delta Force on the Steam Deck.
| Release Date | 12/4/2024 |
| Developer | Team Jade |
| Publisher | TiMi Studio Group |
| Steam App Id | 2507950 |
6. Team Fortress 2
Nine distinct classes provide a broad range of tactical abilities and personalities. Constantly updated with new game modes, maps, equipment and, most importantly, hats!
Team Fortress 2 has achieved a Player Score of 89, placing it in the #6 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 1,136,772 reviews on Steam. This breaks down to a total of 1,013,625 positive reviews and 123,147 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is possible to play Team Fortress 2 on the Steam Deck (though some functionality may be limited).
7. tModLoader
Dig, Fight, and Build your way through the world of player-created mods on Terraria with tModLoader - this DLC makes modding Terraria a reality!
tModLoader has achieved a Player Score of 96, placing it in the #7 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 291,845 reviews on Steam. This breaks down to a total of 283,443 positive reviews and 8,402 negative reviews — making it "Overwhelmingly Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play tModLoader on the Steam Deck (though some functionality may be limited).
8. Once Human
Once Human is a multiplayer open-world survival game set in a strange, post-apocalyptic future. Unite with friends to fight monstrous enemies, uncover secret plots, compete for resources, and build your own territory. Once, you were merely human. Now, you have the power to remake the world.
Once Human has achieved a Player Score of 73, placing it in the #8 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 116,927 reviews on Steam. This breaks down to a total of 85,857 positive reviews and 31,070 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Once Human on the Steam Deck.
| Release Date | 7/9/2024 |
| Developer | Starry Studio |
| Publisher | Starry Studio |
| Steam App Id | 2139460 |
9. PUBG: BATTLEGROUNDS
Play PUBG: BATTLEGROUNDS for free. Land on strategic locations, loot weapons and supplies, and survive to become the last team standing across various, diverse Battlegrounds. Squad up and join the Battlegrounds for the original Battle Royale experience that only PUBG: BATTLEGROUNDS can offer.
PUBG: BATTLEGROUNDS has achieved a Player Score of 59, placing it in the #9 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 2,487,832 reviews on Steam. This breaks down to a total of 1,469,639 positive reviews and 1,018,193 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run PUBG: BATTLEGROUNDS on the Steam Deck.
| Release Date | 12/21/2017 |
| Franchise | KRAFTON, Inc. |
| Developers | |
| Publisher | KRAFTON, Inc. |
| Steam App Id | 578080 |
10. Dark and Darker
An unforgiving hardcore fantasy FPS dungeon PvPvE adventure. Band together with your friends and use your courage, wits, and cunning to uncover mythical treasures, defeat gruesome monsters, while staying one step ahead of the other devious treasure-hunters.
Dark and Darker has achieved a Player Score of 71, placing it in the #10 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 62,628 reviews on Steam. This breaks down to a total of 44,711 positive reviews and 17,917 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Dark and Darker on the Steam Deck (though some functionality may be limited).
More Free Online Co-Op Games
Explore even more rankings for the 100 best free Online Co-Op games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 553,999 | 8/21/2012 | 87 | Free | Steam Charts | |
| 385,822 | 12/6/2024 | 80 | Free | Steam Charts | |
| 285,698 | 7/9/2013 | 81 | Free | Steam Charts | |
| 48,652 | 3/25/2013 | 87 | Free | Steam Charts | |
| 47,100 | 12/4/2024 | 70 | Free | Steam Charts | |
| 31,816 | 10/10/2007 | 89 | Free | Steam Charts | |
| 23,319 | 5/16/2020 | 96 | Free | Steam Charts | |
| 19,729 | 7/9/2024 | 73 | Free | Steam Charts | |
| 17,771 | 12/21/2017 | 59 | Free | Steam Charts | |
| 10,184 | 6/7/2024 | 71 | Free | Steam Charts | |
 | 9,518 | 12/7/2023 | 77 | Free | Steam Charts | |
 | 8,512 | 8/27/2024 | 59 | Free | Steam Charts | |
 | 7,015 | 10/17/2017 | 81 | Free | Steam Charts | |
 | 6,450 | 11/15/2017 | 77 | Free | Steam Charts | |
 | 6,338 | 6/30/2024 | 57 | Free | Steam Charts | |
 | 6,016 | 9/30/2021 | 46 | Free | Steam Charts | |
 | 5,267 | 8/9/2024 | 93 | Free | Steam Charts | |
 | 4,568 | 10/23/2013 | 89 | Free | Steam Charts | |
 | 3,562 | 11/21/2024 | 76 | Free | Steam Charts | |
 | 3,529 | 3/25/2024 | 83 | Free | Steam Charts |
Soures & References
Steambase has best-in-class data powered directly by Steam, our data partners, and in-house experts. Player counts and rankings are enriched, analyzed, and updated in real-time to ensure we surface the most up-to-date insights. Learn more about the Steambase approach to data collection and our review methodology.
- Valve Corporation. (2025, January 15). Steam Store. Steam Store.
- Valve Corporation. (2025, January 15). Counter-Strike 2 on Steam. Steam Store.
- Valve Corporation. (2025, January 13). Marvel Rivals on Steam. Steam Store.
- Valve Corporation. (2025, January 9). Dota 2 on Steam. Steam Store.
- Valve Corporation. (2025, January 6). Warframe on Steam. Steam Store.
- Valve Corporation. (2025, January 15). Delta Force on Steam. Steam Store.
- Valve Corporation. (2025, January 3). Team Fortress 2 on Steam. Steam Store.
- Valve Corporation. (2025, January 12). tModLoader on Steam. Steam Store.
- Valve Corporation. (2025, January 14). Once Human on Steam. Steam Store.
- Valve Corporation. (2025, January 9). PUBG: BATTLEGROUNDS on Steam. Steam Store.
- Valve Corporation. (2025, January 15). Dark and Darker on Steam. Steam Store.