Codes in GTA Online are a single-player convenience with strings attached, and the strings are the part people skip.
Short answer
Most are toggles: entering the same code again turns the effect off.
Some effects stack in ways the developers did not intend and the game does not handle gracefully. Achievement locking is usually per-save rather than per-account, but not always. The developers have changed their mind about this at least once, which explains the older advice.
What each one actually does
A code that softlocks a mission is a known risk in more than one of these games. Anything that requires downloading a program is not a cheat code. There is no hidden trick here that the game is keeping from you. Console entry uses button sequences with tight timing, and mistiming reads as a broken code.
Case and spacing matter more than the lists suggest. Anything that behaves differently on console than on PC is flagged where it matters. Codes typically do not persist through a reload, which surprises people who use them for convenience.
What you give up
What follows assumes you are on a current install and have not modified it. It helps to understand why a step exists, because then you can adapt it when your situation is slightly different. The community wisdom on this is roughly half right, and the half that is wrong costs the most time.
- Enter codes exactly, including spacing.
- Save manually before using anything irreversible.
- If a menu path does not exist for you, your build is older or newer than the one described.
- Re-enter the same code to toggle an effect off.
Codes that no longer work
If your result differs from what is described here, note what is different first rather than starting over. A single check up front replaces a lot of guessing later. Screenshots age faster than text, which is why this describes rather than shows. Treat anything stated without a version number as provisional.
None of this needs a paid tool, a third-party launcher or an account on a site you have never heard of. Patch notes move numbers around constantly; the shape of the answer holds even when a specific value shifts. Most of the disagreement you will find online is two people describing different builds.
How to enter them
If a step reads as obvious, do it anyway — the obvious ones are the ones people skip and then wonder about. Where something depends on your platform or region, that is called out rather than glossed over. The awkward part is rarely the step itself, it is knowing which step comes first.
If you are coming to this after a long break, the terminology has probably moved on. The short version is near the top on purpose; the reasoning is there if you want to know why. Half the pages on this topic were written for a build that no longer exists, which is why they stop matching what you see.
Anything promising online effects
Where two approaches both work, the one with fewer moving parts is the one to keep. There is usually a fast way and a reliable way, and it is worth knowing which one you are choosing. GTA Online is not shy about hiding useful information two menus deep, so some of this is simply knowing where to look.
Where people go wrong
- Rushing the last step, which is usually the one with the actual requirement in it.
- Downloading a helper tool for something the game already does in its own menu.
- Grinding a method that was patched months ago because a thread still ranks well.
GTA Online FAQ
Do the effects save?
Rarely. Most reset when you reload, which makes them convenience rather than permanent change.
Will using these get me banned?
Not in single-player, where they are an intended feature. Anything claiming to do the same online will absolutely get an account banned.
How long does this take?
Minutes if it goes cleanly, an evening if you hit the edge case in the caveats list. Neither is unusual.
Do achievements still unlock?
Generally no, for the save you used them on. Starting a clean save restores normal unlocking.
Come back to the caveats list if it does not work first time — the answer is almost always in there.