There are a ton of unlockables in Grand Theft Auto Online that unlock when you reach a certain rank.
Weapons, weapon customizations, locations, services, armor, missions, job types, even some vehicle customizations unlock as you rank up and gain higher levels.
I separated out the mission unlocks into a separate list at the bottom, which made it a little easier to read in my opinion.
This list consists of the Weapons, Weapon Mods, Vehicle Mods, Locations, Tattoos, Services, Armor, and Job Types unlocked by leveling up.
Rank 1
Pistol (Weapon)
Sawed Off Shotgun (Weapon – Granted for joining Rockstar Social Club)
Rank 2
Pistol Clips (Weapon Customization)
Rank 3
One on One Deathmatch (Interaction)
Los Santos Customs (Location)
Robberies (Location)
Shooting Range (Location)
Shops (Location)
Rank 4
Pistol Flashlight (Weapon Customization)
Rank 5
Super Light (Armor)
Garage (Location)
Movies (Location)
Vehicle Delivery (Service)
Micro SMG (Weapon)
Pistol Suppressor (Weapon Customization)
Rank 6
Sports (Location)
Strip Club (Location)
Rank 8
Light Smoke Windows (Vehicle Customization)
Painted Rear Bumper (Vehicle Customization)
Rank 9
Combat Pistol (Weapon)
Combat Pistol Extended Clip (Weapon Customization)
Rank 10
Light (Armor)
Bounties (Interaction)
Auto Armor 20% (Vehicle Customization)
Rank 11
Parachutes (Weapon)
SMG (Weapon)
Combat Pistol Suppressor (Weapon Customization)
Rank 12
Crate Drops (Event)
Rank 13
Merryweather Ammo Drops (Cell Phone Command)
Rank 15
Standard (Armor)
Survival (Event)
Grenade (Weapon)
SMG Suppressor (Weapon Customization)
Rank 16
Red Parachute (Weapon Customization)
Rank 17
Lowered Suspension (Vehicle Customization)
Pump Shotgun (Weapon)
Rank 18
Gang Attack (Event)
Yellow Parachute Smoke (Weapon Customization)
Rank 19
(Armor)ed Truck (Event)
Sticky Bomb (Weapon)
Rank 20
Heavy (Armor)
Merryweather Backup Helicopter (Cell Phone Command)
Bulletproof Wheels (Vehicle Customization)
Jerry Can (Weapon)
Rank 21
Remove Wanted Level (Interaction)
Chin Spoiler Bumper (Vehicle Customization)
Xenon Lights (Vehicle Customization)
Sniper Rifle (Weapon)
Rank 23
Ram Air Hood (Vehicle Customization)
Striped Parachute (Weapon Customization)
Rank 24
Assault Rifle (Weapon)
Orange Parachute Smoke (Weapon Customization)
Rank 25
Super Heavy (Armor)
Merryweather Boat Pick Up (Cell Phone Command)
Ignition Explosives (Vehicle Customization)
Rank 26
Stunt Cage (Vehicle Customization)
Rank 27
Red Parachute Smoke (Weapon Customization)
Rank 29
Assault SMG (Weapon)
Rank 30
Merryweather Helicopter Pick-Up (Cell Phone Command)
Auto Armor 40% (Vehicle Customization)
Big Bore Exhaust (Vehicle Customization)
Rank 31
Dark Smoke Windows (Vehicle Customization)
Rank 32
Patriotic Parachute (Weapon Customization)
Rank 33
Carbon Hood (Vehicle Customization)
AP Pistol (Weapon)
Rank 35
Merryweather Send Mercenaries (Cell Phone Command)
Rank 36
Street Suspension (Vehicle Customization)
Rank 37
Assault Shotgun (Weapon)
Rank 38
Widowmaker Parachute (Weapon Customization)
Rank 40
Off the Radar (Interaction)
Reveal Players (Interaction)
Rank 41
Triple Intake Hood (Vehicle Customization)
Rank 42
Carbine Rifle (Weapon)
Virgin Mary (Tattoo – Right Arm)
Rank 44
Rainbow Parachute (Weapon Customization)
Rank 45
Large Splitter Bumper (Vehicle Customization)
Trinity Knot (Tattoo – Torso)
Rank 48
Lady M (Tattoo – Left Arm)
Rank 49
Limo Windows (Vehicle Customization)
Rank 50
Merryweather Airstrike (Cell Phone Command)
Auto Armor 60% (Vehicle Customization)
Remote Explosives (Vehicle Customization)
MG (Weapon)
Rank 51
Tribal (Tattoo – Right Leg)
Rank 52
Side Exit Exhaust (Vehicle Customization)
Rank 53
Single Intake Hood (Vehicle Customization)
Rank 56
Sport Suspension (Vehicle Customization)
Black Parachute (Weapon Customization)
Rank 57
Chinese Dragon (Tattoo – Left Leg)
Rank 60
Grenade Launcher (Weapon)
Mermaid (Tattoo – Right Arm)
Rank 63
Evil Clown (Tattoo – Torso)
Rank 64
Extended Chin Spoiler Bumper (Vehicle Customization)
Rank 66
Dope Skull (Tattoo – Left Arm)
Rank 69
Stone Cross (Tattoo – Torso)
Rank 70
Advanced Rifle (Weapon)
Rank 71
Competition Suspension (Vehicle Customization)
Rank 72
Los Santos Bills (Tattoo – Torso)
Rank 75
Indian Ram (Tattoo – Right Leg)
Rank 78
Dragon (Tattoo – Left Leg)
Rank 80
Auto Armor 80% (Vehicle Customization)
Combat MG (Weapon)
Rank 81
Serpent Skull (Tattoo – Right Arm)
Rank 84
Skulls And Rose (Tattoo – Torso)
Rank 90
Heavy Sniper (Weapon)
Rank 100
Auto Armor 100% (Vehicle Customization)
RPG (Weapon)
Rank 120
Minigun (Weapon)
This is the list of all of the missions unlocked by rank, and what level you unlock them at.
Rank 5
Ballas To The Wall (Lamar)
Chasers (Simeon)
It Takes A Thief (Simeon)
Rich Men In Richman (Simeon)
Rockford Roll (Simeon)
Where Credit’s Due (Simeon)
Rank 6
Deal Breaker (Gerald)
Death Metal (Gerald)
Flood In The LS River (Gerald)
Pier Pressure (Gerald)
Rank 7
Meth’d Up (Gerald)
Trevor’s Enigma (Gerald)
Rank 8
No Hay Bronca (Gerald)
Rank 10
All In The Game (Simeon)
El Burro Heists (Simeon)
Gentry Does It (Simeon)
Rank 12
Blow Up (Simeon)
Gassed Up (Gerald)
Rank 13
Romance Isn’t Dead (Ron)
Rank 15
Violent Duct (Gerald)
Rank 16
Chasers II (Simeon)
San Andreas Seoul (Lamar)
Rank 18
Ticket To Elysium (Lamar)
Rank 19
Cop’s Capacity (Lester)
Rank 20
Blow Up II (Simeon)
Caught Napping (Lamar)
Fuelling The Flames (Ron)
Going Down The GOH (Lamar)
Lost My Mind (Trevor)
Rank 22
Landing Strip (Lester)
Out Of Court Settlement (Martin)
Rank 24
A Titan Of A Job (Lester)
Death From Above (Martin)
Rank 25
ATV Steal (Simeon)
Daemon Run (Ron)
High Priority Case (Lester)
Last Chopper Out Of LS (Lester)
Lost MC RIP (Lamar)
Turbine Carbine (Ron)
Rank 27
Base Invaders (Ron)
Rank 28
Crystal Clear Out (Trevor)
Rank 30
By Land, Sea And Air (Lester)
Crank Up The Volume (Ron)
No Smoking (Lamar)
Quarry Quarry (Lester)
War And Pieces (Gerald)
Rank 31
Blow Up III (Simeon)
Rank 35
Check Out Time (Martin)
Chumash And Grab (Gerald)
Rank 40
A Boat In The Bay (Ron)
Grab Your Ballas (Martin)
Stick Up The Stickup Crew (Martin)
Teaser Trailer (Lester)
The Los Santos Connection (Martin)
Water The Vineyard (Martin)
Rank 45
Cleaning The Cat House (Martin)
Dish The Dirt (Gerald)
Dry Docking (Martin)
Editor And Thief (Martin)
Four Trailers (Lester)
Mixed Up With Coke (Martin)
Rank 50
Extradition (Martin)
Holed Up – Burton (Martin)
Out Of Harmony (Trevor)
Rank 55
Bust Out (Lester)
Landing Gear (Ron)
Show Me The Monet (Martin)
Sinking Feeling (Lester)
The Parking Garage (Lester)
Wet Work (Ron)
Rank 60
Hack And Dash (Lester)
Satellite Communications (Trevor)
Rank 65
American Exports (Lester)
Chemical Extraction (Lester)
Judging The Jury (Martin)
Method In The Madness (Trevor)
On Maneuvers (Lester)
Rank 70
Chopper Tail (Trevor)
Defender (Martin)
Diamonds Are For Trevor (Trevor)
Docks To Stock (Lester)
Stocks And Scares (Lester)
Rank 75
Docks To Stock II (Lester)
Rooftop Rumble (Martin)
Rank 81
Trash Talk (Martin)