Free Online Co-Op Games on Steam
Steam currently has 6,939 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 4/25/2025.
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 86. Its score was calculated by analyzing a total of 8,734,128 reviews on Steam. This breaks down to a total of 7,578,427 positive reviews and 1,155,701 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. PUBG: BATTLEGROUNDS
PUBG: BATTLEGROUNDS, the high-stakes winner-take-all shooter that started the Battle Royale craze, is free-to-play! Drop into diverse maps, loot unique weapons and supplies, and survive in an ever-shrinking zone where every turn could be your last.
PUBG: BATTLEGROUNDS has achieved a Player Score of 59, placing it in the #2 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 2,538,798 reviews on Steam. This breaks down to a total of 1,507,140 positive reviews and 1,031,658 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 |
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 2,472,363 reviews on Steam. This breaks down to a total of 2,015,406 positive reviews and 456,957 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. 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 64, placing it in the #4 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 101,376 reviews on Steam. This breaks down to a total of 65,809 positive reviews and 35,567 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 Delta Force on the Steam Deck.
| Release Date | 12/4/2024 |
| Developers | |
| Publisher | TiMi Studio Group |
| Steam App Id | 2507950 |
5. 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 #5 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 270,650 reviews on Steam. This breaks down to a total of 217,753 positive reviews and 52,897 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 |
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 1,152,711 reviews on Steam. This breaks down to a total of 1,033,889 positive reviews and 118,822 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. 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 #7 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 615,632 reviews on Steam. This breaks down to a total of 538,715 positive reviews and 76,917 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 |
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 126,042 reviews on Steam. This breaks down to a total of 93,129 positive reviews and 32,913 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. 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 #9 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 308,527 reviews on Steam. This breaks down to a total of 299,608 positive reviews and 8,919 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).
10. Overwatch® 2
Overwatch 2 is a critically acclaimed, team-based shooter game set in an optimistic future with an evolving roster of heroes. Team up with friends and jump in today.
Overwatch® 2 has achieved a Player Score of 24, placing it in the #10 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 337,724 reviews on Steam. This breaks down to a total of 78,663 positive reviews and 259,061 negative reviews — making it "Mostly Negative" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Overwatch® 2 on the Steam Deck (though some functionality may be limited).
| Release Date | 8/10/2023 |
| Franchise | Blizzard |
| Developer | Blizzard Entertainment, Inc. |
| Publisher | Blizzard Entertainment, Inc. |
| Steam App Id | 2357570 |
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 | ||||
|---|---|---|---|---|---|---|
| 1,004,096 | 8/21/2012 | 86 | Free | Steam Charts | |
| 329,254 | 12/21/2017 | 59 | Free | Steam Charts | |
| 328,184 | 7/9/2013 | 81 | Free | Steam Charts | |
| 68,626 | 12/4/2024 | 64 | Free | Steam Charts | |
| 67,380 | 12/6/2024 | 80 | Free | Steam Charts | |
| 41,268 | 10/10/2007 | 89 | Free | Steam Charts | |
| 31,782 | 3/25/2013 | 87 | Free | Steam Charts | |
| 28,005 | 7/9/2024 | 73 | Free | Steam Charts | |
| 23,067 | 5/16/2020 | 96 | Free | Steam Charts | |
| 21,685 | 8/10/2023 | 24 | Free | Steam Charts | |
 | 12,370 | 6/7/2024 | 70 | Free | Steam Charts | |
 | 8,571 | 9/30/2021 | 47 | Free | Steam Charts | |
 | 7,322 | 12/8/2023 | 77 | Free | Steam Charts | |
 | 6,556 | 11/15/2017 | 76 | Free | Steam Charts | |
 | 6,204 | 6/30/2024 | 56 | Free | Steam Charts | |
 | 5,217 | 11/9/2016 | 78 | Free | Steam Charts | |
 | 5,060 | 3/6/2025 | 72 | Free | Steam Charts | |
 | 4,990 | 10/17/2017 | 81 | Free | Steam Charts | |
 | 3,609 | 5/5/2020 | 77 | Free | Steam Charts | |
 | 3,434 | 8/9/2024 | 93 | 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, April 25). Steam Store. Steam Store.
- Valve Corporation. (2025, April 25). Counter-Strike 2 on Steam. Steam Store.
- Valve Corporation. (2025, April 16). PUBG: BATTLEGROUNDS on Steam. Steam Store.
- Valve Corporation. (2025, April 23). Dota 2 on Steam. Steam Store.
- Valve Corporation. (2025, April 25). Delta Force on Steam. Steam Store.
- Valve Corporation. (2025, April 24). Marvel Rivals on Steam. Steam Store.
- Valve Corporation. (2025, April 23). Team Fortress 2 on Steam. Steam Store.
- Valve Corporation. (2025, April 16). Warframe on Steam. Steam Store.
- Valve Corporation. (2025, April 24). Once Human on Steam. Steam Store.
- Valve Corporation. (2025, April 24). tModLoader on Steam. Steam Store.
- Valve Corporation. (2025, April 24). Overwatch® 2 on Steam. Steam Store.