Free Online Co-Op Games on Steam
Steam currently has 6,790 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 3/21/2025.
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 8,675,405 reviews on Steam. This breaks down to a total of 7,530,450 positive reviews and 1,144,955 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. 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 #2 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 2,460,897 reviews on Steam. This breaks down to a total of 2,006,660 positive reviews and 454,237 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).
3. 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 #3 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 2,524,338 reviews on Steam. This breaks down to a total of 1,496,671 positive reviews and 1,027,667 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 |
4. 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 #4 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 252,540 reviews on Steam. This breaks down to a total of 203,278 positive reviews and 49,262 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 |
5. 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 #5 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 612,957 reviews on Steam. This breaks down to a total of 536,331 positive reviews and 76,626 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 |
6. 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 65, placing it in the #6 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 94,324 reviews on Steam. This breaks down to a total of 62,162 positive reviews and 32,162 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 |
| Developer | Team Jade |
| Publisher | TiMi Studio Group |
| Steam App Id | 2507950 |
7. 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 #7 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 1,149,120 reviews on Steam. This breaks down to a total of 1,029,316 positive reviews and 119,804 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).
8. 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 #8 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 304,308 reviews on Steam. This breaks down to a total of 295,508 positive reviews and 8,800 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).
9. 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 #9 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 123,750 reviews on Steam. This breaks down to a total of 91,314 positive reviews and 32,436 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 |
10. FragPunk
FragPunk is a thrilling 5v5 hero shooter where Shard Cards allow you to break the rules of combat and ensure that no two rounds are ever the same. Get ready to unleash your skills!
FragPunk has achieved a Player Score of 72, placing it in the #10 spot for the best free Online Co-Op games. Its score was calculated by analyzing a total of 30,342 reviews on Steam. This breaks down to a total of 22,219 positive reviews and 8,123 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 FragPunk on the Steam Deck.
| Release Date | 3/6/2025 |
| Developer | Bad Guitar Studio |
| Publisher | Bad Guitar Studio |
| Steam App Id | 2943650 |
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 | ||||
|---|---|---|---|---|---|---|
| 1,327,461 | 8/21/2012 | 87 | Free | Steam Charts | |
| 546,790 | 7/9/2013 | 81 | Free | Steam Charts | |
| 485,484 | 12/21/2017 | 59 | Free | Steam Charts | |
| 112,348 | 12/6/2024 | 80 | Free | Steam Charts | |
| 66,972 | 3/25/2013 | 87 | Free | Steam Charts | |
| 65,797 | 12/4/2024 | 65 | Free | Steam Charts | |
| 49,462 | 10/10/2007 | 89 | Free | Steam Charts | |
| 39,382 | 5/16/2020 | 96 | Free | Steam Charts | |
| 26,447 | 7/9/2024 | 73 | Free | Steam Charts | |
| 25,691 | 3/6/2025 | 72 | Free | Steam Charts | |
 | 16,779 | 12/8/2023 | 77 | Free | Steam Charts | |
 | 13,680 | 10/23/2013 | 88 | Free | Steam Charts | |
 | 13,420 | 9/30/2021 | 47 | Free | Steam Charts | |
 | 12,128 | 6/30/2024 | 57 | Free | Steam Charts | |
 | 11,616 | 10/17/2017 | 81 | Free | Steam Charts | |
 | 10,953 | 10/3/2021 | 85 | Free | Steam Charts | |
 | 8,993 | 11/9/2016 | 78 | Free | Steam Charts | |
 | 8,189 | 6/7/2024 | 70 | Free | Steam Charts | |
 | 7,583 | 11/15/2017 | 76 | Free | Steam Charts | |
 | 7,450 | 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, March 21). Steam Store. Steam Store.
- Valve Corporation. (2025, March 21). Counter-Strike 2 on Steam. Steam Store.
- Valve Corporation. (2025, March 28). Dota 2 on Steam. Steam Store.
- Valve Corporation. (2025, March 19). PUBG: BATTLEGROUNDS on Steam. Steam Store.
- Valve Corporation. (2025, March 28). Marvel Rivals on Steam. Steam Store.
- Valve Corporation. (2025, March 28). Warframe on Steam. Steam Store.
- Valve Corporation. (2025, March 28). Delta Force on Steam. Steam Store.
- Valve Corporation. (2025, March 21). Team Fortress 2 on Steam. Steam Store.
- Valve Corporation. (2025, March 1). tModLoader on Steam. Steam Store.
- Valve Corporation. (2025, March 27). Once Human on Steam. Steam Store.
- Valve Corporation. (2025, March 28). FragPunk on Steam. Steam Store.