PoE Regex 101: what the search box actually does

Every search box in Path of Exile — the stash, the vendor window, the map device, the atlas — takes a regular expression. Most people find this out from a wall of punctuation somebody pasted in a thread, use it, and never learn what it says.

You do not need to learn. That is what the regex builders here are for. But knowing what the game is actually doing with that string turns it from a magic word into a tool you can aim, so this is the short version.

What the game does with your string

It matches the string against the text the window can show you. Not the item’s data — the words printed on it.

That distinction is the whole subject. The game does not know you meant “a map with no reflect”; it knows whether the letters you typed appear anywhere in what is printed on the item. Everything else follows from that.

Three consequences worth having in your head:

• You are matching printed text, so language matters. A string built for an English client will not match a Russian one, because the words are different words. The builders here handle both: switch the site language and the patterns switch with it.
• Partial matches count. Typing reflect matches every line containing those letters, wherever they sit.
• Case is ignored, so you never need to worry about it.

The 250-character wall

The field takes 250 characters. That is the real constraint, and it is what makes hand-written regex painful — you can express nearly anything, but not much of it at once.

Which is where most of the cleverness in a good pattern goes. If you want to exclude “Monsters reflect 18% of Elemental Damage”, you do not write that sentence. You write the shortest piece of text that appears on that mod and on nothing else the window can show. Sometimes that is four characters.

Finding those fragments by hand is the tedious part, and it is the part this site does for you: every pattern in the builders is the shortest unique fragment for its mod, checked against every equipment base, unique, gem and flask name in the game before it ships. That is what lets you fit a dozen mods inside the limit instead of three.

The two questions

Every regex you build is answering one of two questions, and they are opposites.

“What will I not run?” — rolling maps. You are about to run this map and there are modifiers that make it not worth it. You want a string that lights up a map when it carries none of them.

“What am I looking for?” — flasks, tablets, relics, vendor windows. You want a string that lights up an item when it carries at least one of the things you want.

The builders here know which question their category is for, so you tick and it does the rest. On maps you tick what you refuse; on flasks you tick what you are hunting. Waystones in PoE 2 are the odd one that asks both at once, because that is genuinely how people roll them.

What is here for PoE 1

Eight builders, each one its own page:

• Map mods — the big one. Tick what you will not run, add minimum quantity or pack size, get the string for the map device.
• Scarabs, Tattoos, Runegrafts — these match item names rather than mods, and they carry live prices from our own exchange data, so you can ask for “everything above 5 chaos” instead of remembering which ones matter this league.
• Flasks — what you are rolling for.
• Vendor search — 592 mod lines, plus a socket panel: links, colours, and how many sockets, without spelling out every order the game might print them in.
• Chaos recipe — item level bands and the switches, no mod list at all.
• Price in stash — find what you priced under 10 chaos, or between two numbers.

Keeping the ones you build

A string you tuned for one league’s maps is worth having next week, not just tonight. Every builder saves named setups with a note, and a setup is the same thing a shared link carries — so you can hand one to a friend without converting anything.

Without an account they are kept in the browser you built them in, five per category, and the sixth pushes the oldest out. An account keeps the same five and moves them off the browser, so the same setups open on your phone and on whatever machine you play from. A Patreon subscription raises how many each category holds, and room is the only thing it raises: no tool on this site is behind it.

Two things that surprise people

A socket request can eat your whole budget. Asking for three named colours anywhere in a six-link is over two thousand characters, because every order the game might print them in has to be spelled out. Narrow the chain and it collapses to a fraction of that. The builder shows the cost as you go, which is the point — you can see the expensive question before you ask it.

The meter matters more than the string. Every builder here counts your 250 characters as you tick. When you go over, the answer is not a cleverer pattern; it is dropping the mods you would merely settle for and keeping the ones you would actually buy.

The honest limits

A regex tells you what an item says, not what it is worth. It cannot do arithmetic, so “total resistance above 100” is not a thing you can ask for. It cannot compare two numbers. And it matches text, so a mod that prints differently in two places is two patterns, not one.

Within that, it is the fastest filter in the game, and it costs one paste.

Start with map mods if you are rolling maps tonight, or the section page if you want to see the rest.