Plants vs. Zombies Web Version was a free version of the game that was available at the PopCap Games official website. There were three modes: Adventure Mode, Survival and Puzzle. In the Adventure Mode of this version the player could only progress until they finish level 2-4 before they must start again as a new player. However, if one unlocked the Survival and Puzzle modes on one computer previously, they will be able to continue playing those modes. Survival Mode on the web version was a modified version of Survival: Endless which took place during the night, and the player could only choose four plants at a time. Puzzle Mode consisted of a modified version of Vasebreaker. The player's progress was lost on the Survival and Puzzle modes if they quit, unlike the full version.
- Cherry Bomb
- Snow Pea
- Grave Buster
There were eight zombies in the Web version.
- Flag Zombie
- Conehead Zombie
- Buckethead Zombie
- Pole Vaulting Zombie
- Newspaper Zombie
- Screen Door Zombie
- Giga-Football Zombie
This was a unique version of Survival: Endless only available for this version. It had quite unique features, such as not being available to select more than four plants, limited kinds of plants available, and the Giga-Football Zombie. The Giga-Football zombie took the same amounts of damage as the Gargantuar (3000 damage), but was as fast as the Football Zombie. The presence of this zombie as well the large mass of zombies appearing (about 400 Giga-Football Zombies until level 15, about 3000 in total) makes this level extremely hard, being virtually impossible to get past wave 20. Chompers could devour the Giga-Football Zombie in one bite, which was a recommended way to combat it as it couldn't be killed by one instant kill.
- The zombies in the online version would usually have no bone seen upon losing their arm.
- There was a Survival: Night (Endless) here, because if it took place at daytime, mushrooms would not be able to wake up, since the player never gets the Coffee Bean.
- The zombies would not attempt to eat the instant kills (except Chomper), similar to Plants vs. Zombies 2.
- There were two glitches with the Newspaper Zombie: when falling to die, a bone in his arm would appear, and his eyes would flash angry for no reason.
- The modes were on different buttons, unlike the full version.
- If the player beated the game, the plants would reset, so they couldn't use mushrooms during the day.
- Instead of the Potato Mine the player would get the Squash.
- One could see the silhouettes of the Ice-shroom, Doom-shroom, Lily Pad, Potato Mine, Threepeater, Tangle Kelp, Jalapeno, Spikeweed, Torchwood, Tall-nut, Cactus and Blover when the player had unlocked all the Online Plants.
- The Snow Pea made a different sound effect when it shoots frozen peas on the online version than it normally does (a "jingle bell"-like sound effect).
- The seed packets were much bigger in this version.
- There was no shadow below the plants or zombies.
- If the player put their mouse over the Giga-Football Zombie it would've said "Football Zombie." This is because there was no Football Zombie in this version.