Portal 2: Complete Guide

A guide to Portal 2's single-player and co-op campaigns: portal mechanics and puzzle-solving habits, every test element, a spoiler-light chapter outline, easy-to-miss achievements, co-op tips, and the best community content and mods to play afterward.

Researched September 2026 — current as of the June 2026 Valve updates (credits fixes, security fixes, Linux launch fix). The game is otherwise complete; check the linked sources if something differs.

Quick Start

Momentum is conserved through portals. "Speedy thing goes in, speedy thing comes out." Falling into a floor portal flings you out of a wall portal at the same speed.
Portals only go on white, flat surfaces. Dark metal, glass, and grates won't take portals. Look for white panels first when entering a room.
Stop and look around. Most puzzles are solved by noticing one surface or element you missed. Stand at the entrance and scan the whole room.
Everything is one idea at a time. The game introduces a new element, tests it, then combines it. If you're stuck, think about what the last new element does.
You can't really fail. Deaths reset you to a nearby checkpoint in seconds. Experiment freely.
Hold objects to carry them through portals. Cubes, spheres, and turrets can be carried and dropped through portals.
Co-op is a separate campaign. It has its own story and characters, Atlas and P-body. Play it after (or alongside) single-player.
Turn on developer commentary on a second playthrough. It's full of great design insight.
Play community content after. The Perpetual Testing Initiative, workshop maps, and standalone mods like Portal Stories: Mel, Portal Reloaded, and Portal: Revolution extend the game for years.

Controls (PC defaults)

Action	Default
Move	W A S D
Jump	Space
Crouch	Ctrl
Blue portal	Left mouse
Orange portal	Right mouse
Use / pick up	E

Crouching while jumping lets you clear taller ledges. Co-op adds a ping tool and gestures. Check Options > Keyboard for their binds on your setup. Pinging a surface tells your partner exactly where you want a portal.

Test Elements

Element	What it does	Key trick
Weighted Storage Cube	Holds down buttons	The first thing to look for in any room
Companion Cube	A cube with hearts	Behaves like a storage cube
Redirection Cube	Redirects laser beams	Aim it at laser catchers
Edgeless Safety Cube	Sphere-shaped cube	Rolls. Used with sphere buttons
Thermal Discouragement Beam (laser)	Burns you and powers receivers	Portals redirect it. Lasers also kill turrets
Aerial Faith Plate	Launches you on a set arc	Portals can redirect the launch
Hard Light Bridge	A walkable light bridge	Portal it to put a bridge anywhere, including as a wall or shield
Excursion Funnel	A tractor beam that carries you	Polarity can reverse. Portal it to travel anywhere
Repulsion Gel (blue)	Bounces you	Coat floors and walls to jump high
Propulsion Gel (orange)	Makes you run fast	Long runways plus a portal fling = huge distance
Conversion Gel (white)	Makes any surface portalable	Shoot it through a portal to coat new surfaces
Turrets	Shoot you	Knock them over, block with cubes or bridges, or burn with lasers
Pneumatic Diversity Vent	Sucks up objects	Mostly environmental
Buttons and pedestals	Trigger doors and elements	Some are timed

Puzzle-Solving Habits

Find the exit first. Then work backward: what needs to happen to open it?
List every portalable surface. The solution almost always uses a specific one.
Count the objects. If there's one cube and two buttons, something else must hold one down (a turret, a bridge, a funnel).
Think about flow. Gels, lasers, bridges, and funnels all "flow" through portals. Ask where you want that flow to go.
Flings. When a gap is too far, look for a high drop you can fall into. Momentum is the answer.
Timers aren't the puzzle. Timed buttons usually mean you need a portal pre-placed so you can move fast.
Take a break. Solutions often appear after you walk away for a minute.

Single-Player Chapter Outline (Spoiler-Light)

Chapter	Name	What to expect
1	The Courtesy Call	Waking up, meeting Wheatley, getting a portal device
2	The Cold Boot	GLaDOS returns. Classic test chambers with lasers and bridges
3	The Return	More testing under GLaDOS
4	The Surprise	Escape plans begin
5	The Escape	Breaking out, turret sabotage, neurotoxin
6	The Fall	Deep underground. Old Aperture, gels begin
7	The Reunion	1950s–70s test chambers with Cave Johnson
8	The Itch	Wheatley's tests. Combining everything
9	The Part Where He Kills You	The finale

Tips by stage:

Chapters 1 to 3 teach portals, cubes, lasers, and bridges. Take your time.
Chapter 6 to 7 is where gels arrive. Old Aperture rooms are huge. Look for gel sources and pipes first.
Chapter 8 mixes everything. Many chambers have more than one solution.
Chapter 9 is a scripted finale. Keep moving and use portals quickly.

Co-op Campaign

Two robots, Atlas (blue) and P-body (orange), each with their own two portals. That's four portals, which opens up puzzles impossible in single-player.

Courses:

Course	Theme
1. Team Building	Basics of four-portal play
2. Mass and Velocity	Flings and faith plates
3. Hard-Light Surfaces	Light bridges
4. Excursion Funnels	Tractor beams
5. Mobility Gels	Gels
6. Art Therapy	The Peer Review DLC course (free)

Co-op tips:

Use the ping tool. Point exactly where you want a portal instead of explaining it.
Use the countdown. Timed jumps are easier with the built-in countdown gesture.
One person experiments while the other watches. Then swap.
Split screen works on PC and was fixed in a February 2024 update.
Play with someone you trust. Valve patched several co-op exploits in 2024 and 2025, and more security fixes in June 2026. Keep the game updated.

Achievements Worth Knowing

Most achievements come naturally from finishing the campaigns. A few are easy to miss:

Achievement	Requirement
Door Prize	Examine all the vitrified test chamber doors
Portrait of a Lady	Find the hidden portrait
Smash TV	Break 11 test chamber monitors
Final Transmission	Find the hidden signal in one of the Rat Man's dens
Overclocker	Complete Test Chamber 10 in 70 seconds
Preservation of Mass	"Break the rules in Test Chamber 07"
Pit Boss	"Show that pit who's boss"
Ship Overboard	"Discover the missing experiment"
Schrodinger's Catch	Catch a blue-painted box before it touches the ground
Pturretdactyl	Use an Aerial Faith Plate to launch a turret
Stalemate Associate	"Press the button!"

The quoted ones are deliberately cryptic in-game. If you want them in one run, look up their exact chamber on the Portal Wiki before you pass that chapter, since you'd otherwise need chapter select to go back.

Co-op has its own set, including several that need the gesture or ping tools and a specific partner action. Examples:

Talent Show — never lose a cube in Chamber 6 of the Mobility Gels course.
Friends List With Benefits — hug 3 different people on your friends list while playing co-op.
Professor Portal — after finishing co-op, complete the Calibration Course online with a friend who hasn't played before.

Search the achievement list in Steam before your co-op run so you can do them in one go.

Community Content and Mods

Perpetual Testing Initiative (Puzzle Maker) — a built-in editor for making and sharing test chambers through the Steam Workshop. Free.
Steam Workshop — thousands of community chambers. Sort by top rated.
Portal Stories: Mel — a full-length, free standalone mod campaign with a new story and voice acting.
Portal Reloaded — adds a third portal for time travel between two versions of each chamber.
Portal: Revolution — a large free mod campaign set between Portal and Portal 2.
Thinking with Time Machine and Aperture Tag — other well-known mods with new mechanics.

Most mods are separate Steam entries that require you to own Portal 2.

Common Mistakes to Avoid

Ignoring the ceiling and far walls. The key surface is often above you or across a pit.
Assuming you need speed or precision. Portal 2 puzzles rarely require difficult execution. If you're trying hard jumps over and over, there's probably an easier idea.
Forgetting that elements pass through portals. Lasers, bridges, funnels, and gel all do.
Rushing through dialogue. The writing is a huge part of the game. Stop and listen.
Spoiling puzzles too quickly. Give each chamber a few minutes before looking up a solution.
Skipping co-op. It's arguably the best puzzle design in the game.

Advanced Tips

Flings are all about height. The higher you fall, the further you go. Stack portal loops to build speed.
Mid-air portals. You can shoot a new portal while in the air to change your exit point.
Use bridges as shields. Hard light blocks turret fire.
Paint with conversion gel through portals to create new portal surfaces anywhere.
Speedrunners use tricks like crouch-flying and portal bumping. Watch a speedrun after you finish to see the game differently.
Commentary nodes show how Valve playtested puzzles. Great for puzzle design fans.

FAQ

How long is Portal 2? Roughly 8 to 10 hours for single-player on a first run, plus several hours for co-op, depending on how quickly you solve puzzles.

Can I play co-op with a random player? Yes, but it's much better with a friend, voice chat, and the ping tool. Local split screen is also supported.

Do I need to play Portal 1 first? It's recommended for story context but not required. Portal 2 introduces its mechanics from scratch.

Is Portal 2 still updated? Valve pushes occasional fixes, most recently in June 2026 (credits and subtitle fixes, security fixes, and a Linux launch fix).

What should I play after Portal 2? Workshop chambers, Portal Stories: Mel, Portal Reloaded, and Portal: Revolution.

Is the Peer Review DLC included? Yes. The Art Therapy co-op course from Peer Review is part of the game.