While browser games usually don’t offer the same level of detailed gameplay and immersion as installed games for smartphones, PCs, and consoles, they are known to be quite fun as well. You don’t need much time to set it up or get familiar with them either, most of the time browser games are quick and simple and you can start playing in under a minute. This makes them a great fit for occasional gamers. There are many different types to choose from, from online versions of cardboard games to shooting and online casino games.

The convenience and popularity of browser gaming have led to more and more games initially designed for smartphones, PCs, and consoles being adopted so they can run online on browsers as well.

1. Agar.io – In this game, you play as a cell, and your goal is to become the largest one in the arena. You can eat other cells to grow larger, but you need to watch out for bigger cells that can eat you.
   
2. Slither.io – Another game in which you start small and get larger by eating pellets. You can also eat other snakes by making them crash into your body.
   The game is simple yet very addictive and interactive and has been a favorite of many players.
   
3. Online Slots – Online slots are among the most popular online gambling games. Many casinos try to make them as fun as possible, improving visuals and sound effects, adding on new themes, and competing to offer the best slot games online.
   
4. Catan Universe – Catan is a great board game, one of the most popular among the board game community. Designed for 5 to 6 players, you can play it online against friends or as a single-player game against AI opponents. Originally “Settlers of Catan”, now just called Catan, helped make the golden age of board games as it grew in popularity outside of Europe. It’s a classic definitely worth a try if you’ve never played it before.
   
5. Fallen London – originally Echo Bazaar, is a browser game set in “Fallen London”, a fictional gothic version of Victorian London. The game subsequently expanded to a franchise, including other games like Sunless Sea and its sequel Sunless Skies.
   
6. Pokémon Showdown – In a fast-paced Pokémon Showdown you can battle using either a custom or a random team. In the match, you compete against a rival trainer, by selecting different moves and countering the opponent.
7. Run 3 – is a fast-paced running game in which you are navigating through various tunnels and obstacles. The game gets progressively more challenging as you advance, and requires quick reflexes, making it both a challenging and fun experience.
   
8. Wordle – Wordle is based on the idea of a Mastermind code-breaking game, where you would be guessing which color belongs to which field. Here instead of colored balls, you have letters which when stacked in the right order make a word. There are versions of wordle available for other languages also..
   
9. Mathle – A math equivalent to Wordle, where instead of letters you’re required to find the correct numbers and math operators sign, and instead of the words your goal is to guess a math equation.
   
10. 2048 – 2048 is another popular math-based puzzle game where the goal is to merge tiles with the same numbers to reach the number 2048. The game is simple yet challenging, making it a great choice for puzzle lovers.
    
11. Surviv.io – A battle royale game that requires you to survive against other players on a shrinking map. The game has a top-down view and is easy to play, but requires strategy and skill to win.
    
12. Chess – As chess grandmaster Hikaru Nakamura said “Puzzles are the best way to improve pattern recognition.” and chess is definitely one of the games for that. There are quicker and more fun formats such as Blitz and Bullet with a time limit from five minutes to just one minute per player.
    
13. Krunker.io – A fast-paced and exciting first-person shooter game that resembles many traditional FPS games, particularly the Counter-Strike series. The game is lightweight and quick to load, with various game modes and maps to choose from, and you can customize your character to make it unique.
    
14. Among US – A popular game initially played from smartphone apps, now also available to play online from a browser. Your team goal is to find who the imposter is and eject him from the ship before he gets to eliminate all the team members or sabotage the ship. Of course, unless you get assigned the imposter role.
    
15. Tanki Online – One of the most popular browser tank games, it’s played in deathmatch settings, where players gain experience and level up their hull, turret, and armor.

In conclusion, these are some of the most fun online browser games you can play. Some have rather simple gameplay and some are more complex and could hold attention for longer than a quick play.