TOP 3 Free to Play PS4 Games!!

To play online multiplayer games on ps4 requires a PS Plus to subscribe but these below three free to play games doesn't require PSN plus.

1. LOADOUT

Loadout is free to play online multiplayer game on PS4. 

Loadout is a free-to-play multiplayer third-person shooter developed by Edge of Reality, originally made for Microsoft Windows then ported to PlayStation 4, Loadout focuses on arcade-style multiplayer firefights across a variety of modes and uses an over-the-top cartoon gore and wealth of character customization options. Players can alter the appearance of their in-game avatar as well as the properties of their weapons at the cost of some premium in-game currency.^[1] The development of Loadout has since been abandoned and many main developers have been laid off for unknown reasons
It has five game-play modes  Death Snatch, Blitz, Jackhammer, Annihilation, and Extraction, most of which are based around collecting Blutonium, a fictional element.

2. WARFRAME

Warframe is a free-to-play cooperative third-person shooter video game developed by Digital Extremes for Microsoft Windows,PlayStation 4, and Xbox One. In Warframe, players control members of the Tenno, a race of ancient warriors who have awoken from centuries of cryosleep to find themselves at war with different factions.In Warframe, players control members of the Tenno, a race of ancient warriors who have awoken from centuries of cryosleep to find themselves at war with the Grineer, a race of militarized human clones, the Corpus, a mega-corporation with advanced robotics and laser technology, the Infested, disfigured victims of the Technocyte infection, and later the Sentients, an alien force returning from the Tau system after being driven back centuries ago. To fight back, the Tenno use psionically controlled, biomechanical biosuits to channel their unique abilities — the eponymous Warframes.^[1] Later missions reveal that the Warframes are actually biomechanical shells which are connected the conscience of the actual Tenno, human children who were given unpredictable powers by the Void. Those powers led to them being demonized and they were exiled into stasis pods on the Moon. The Tenno and their Warframes were used by the Orokin Empire in a desperate fight against the Sentients and stopped their invasion. However, for unknown reasons, the former turned on the latter and caused the Empire to collapse. The Empire shattered with the remnants becoming the Grineer and the Corpus while the Tenno were placed in stasis until centuries later. Available missions are scattered across the planets of the solar system, the moons Phobos and Europa and dwarf planets Pluto, Ceres, Eris and Sedna. Players can also access missions set in apocket dimension known as The Void through completing junctions on other planets or through Void Fissures, small volatile rifts which react with acquirable Void Relics

3. PLANETSIDE 2

PlanetSide 2 is a free-to-play massively multiplayer online first-person shooter published by Daybreak Game Company and released on November 20, 2012. It is a sequel of PlanetSide which originally was released in 2003. Officially announced on July 7, 2011 at the Sony Fan Fair, the second installment used a new game engine, supported thousands of players in continuous large scale conflict, and featured in-game integration with Twitch.tv. As in the first PlanetSide, PlanetSide 2 chronicles the efforts of three factions as they fight for territorial control of the planet Auraxis. PlanetSide 2 was released for the PlayStation 4 in North America on June 23, 2015.PlanetSide 2 holds the Guinness World Record for the biggest first-person shooter battle with 1158 players recorded in a single battle
PlanetSide 2 is a re-imagining of PlanetSide, featuring the same world and factions, and taking place at roughly the same time period. As in the previous game, it features territory control in an open-world, large battles featuring up to 2000 players per continent on foot or in land/air vehicles. The territory system differs greatly from that of the original, being more free-form and based on a hexagonal territory control system. Former SOE (now DBG) took into account balance issues from the first game. As stated by creative director Matthew Higby, they reward combatants on lower population empires through mechanics such as proportionally increased advancement rates and resources to aid the balance of overall empire saturation on each server as much as possible without force-restricting players from being able to play with their friends.