If you got lost among icons, columns and buttons the first time you opened the tool, you're in the right place. Here we explain everything calmly, without assuming you already know anything.
Three minutes to understand what this tool does before diving into the details.
FoE Optimizer is a Swiss army knife for Forge of Empires. It basically does four things:
Every building in the game, with real stats, even without importing anything.
Import your real city and see what every building you own actually earns you.
Find out exactly what you can build with the kits sitting in your warehouse. It's the tool's most unique feature.
Levels, rarity, inherited bonuses and fragments, all calculated for you.
Everything runs inside your browser: there's no server anywhere receiving your data, no account to create, nothing to install. Close the tab and reopen it — your data is still there, saved on your own device.
How to bring your real city into the tool, and how to stay organized if you play on multiple worlds.
A profile is simply a card that groups together the city, inventory and allies of one account. If you play on multiple worlds (say, a "live" one and a "beta" one), or you have multiple accounts, you can keep them as separate profiles that never mix.
It's the only way to bring your real data into the tool, and it's essentially a special browser bookmark that, when clicked while you're inside Forge of Empires, reads your game data and brings it in here. Here are all the steps:
It's a free extension that reads Forge of Empires data while you play. If you don't have it yet, search for it in your browser's extension store.
Press and hold the wand button 🪄 (at the top of the tool) and drag it up into your browser's bookmarks bar. This creates a special bookmark you can rename however you like.
With Forge of Empires open in the browser and FoE Helper active, click the bookmark you just created. It silently copies all your game data to your computer's clipboard — you won't see anything happen, that's normal.
The tool reads the clipboard, automatically creates a new profile, and imports city, inventory and allies all together. Any profiles you already had are never touched.
| Button | What it does |
|---|---|
| SAVE | Exports all your profiles into a JSON file. Useful as a backup, or to move your data to another device (e.g. from PC to tablet). |
| LOAD | Imports profiles from a previously saved file. They're added to your existing ones, without overwriting anything. |
Since everything only lives in your browser, saving a backup every now and then (especially before switching browsers or devices, or clearing your cache) is a good habit.
The full game catalog: over two thousand buildings, browsable without importing anything.
This is the tab you see the moment you open the tool, even with an empty profile. It contains every building in Forge of Empires — more than 2000 — with their "reference" stats (calculated at the game's final era, the Space Age Space Hub, for a fair comparison).
It's useful for:
The LIGHT / FULL button at the top left changes how much of the database you see: LIGHT shows only the game's "main" buildings (the classic ones, without variants or intermediate levels), FULL shows everything, variants included. If the sheer number of rows feels overwhelming, start with LIGHT.
Your real city, with real numbers — not the theoretical ones from the database.
Once you've imported your city with the magic wand, this tab shows exactly the buildings you own, with stats calculated at your current era (not the final one like in the Database). If you have a building still stuck in the Iron Age, you'll see that era's numbers, not the "endgame" ones.
Compared to the Database, here you'll find a bit more information:
| What you see | What it means |
|---|---|
| Disconnected buildings | A badge flags buildings not connected to the road — they aren't producing the way they should. |
| Unnecessary road | The opposite: buildings connected to the road that actually don't need to be (you're "wasting" connections). |
| Upgrade badge | If you already own the necessary kits (visible in the Inventory tab), an icon flags which buildings you can level up right away. |
| Ally slot | An icon for each copy of the building that can host an ally, filled if occupied (with a tooltip showing the ally's name) or empty if free. |
There's also a map view 🗺️ showing the actual layout of your city, handy for getting a visual overview or exporting an image to share.
The reason this tool exists in the first place: what you can actually build with what you have.
Anyone who's played Forge of Empires for a while knows the problem: your inventory fills up with selection kits, upgrade kits, fragments, and it becomes impossible to tell at a glance what you can actually pull out of all that stuff. This tab solves exactly that.
You import your inventory (again with the magic wand) and the tool calculates, building family by building family, the maximum you can build with the kits you own — level by level, also showing you which specific kits it would use.
If you've never dug into the mechanic, here's the essentials:
Some selection kits — the epic ones — offer options that touch many different families of buildings at once. The tool shows you that kit's potential for each of the families it touches: if you see the same epic kit show up in twelve different spots, that's not a counting error — it means you could use it for any one of those twelve families, but you'll have to pick just one when you actually spend it in-game.
For each buildable family, the tool distinguishes two types of rows:
The Ready buildings only button filters the view to show only what you already physically have in inventory, handy if you want to focus on what to place right now instead of what you might get in the future.
Your allies, their real bonuses, and the fragments you're still collecting.
Once you import your allies, you'll see the ones you own, their level, rarity, and calculated bonuses — including inheritance: a higher-rarity ally automatically inherits the bonuses of lower-rarity versions of the same ally, and the tool adds them all up for you without you having to do the math by hand.
You'll also find fragments: ally pieces that, once you collect enough of them, turn into a full ally. Useful for seeing how close you are to completing the ones you're still working on.
The Owned only button hides the rest of the allies catalog and shows only the ones you actually have, while Show full database does the opposite — handy if you also want to see allies you don't have yet, to get a sense of what to aim for.
The number you see next to every building (EFF) and what it actually means.
Every building (and ally) gets an efficiency score: basically, how much it "earns" for every space cell it occupies in your city. The higher it is, the more that building gives you relative to the space you dedicate to it. The formula, in plain terms:
The bonuses factored into the calculation are the general ones, the Guild Battlegrounds ones and — if you enable them — the Guild Expedition ones. The exact same mechanism applies to both buildings (Database, City, Inventory tabs) and allies (Allies tab): the weights you adjust in the toolbar apply to both at once.
| Weight | What it controls |
|---|---|
| ⚔️ Atk | Fixed at 1.0. It's the reference point everything else is calibrated against. |
| 🛡️ Def | How much defensive bonuses count relative to offensive ones. Default 0.8: defense weighs a bit less than attack. |
| 🔰 BG | The box showing the Attack/Defense weights actually used in the calculation, after subtracting the share reserved for Expeditions. Not editable directly: it updates automatically based on the other controls. |
| ⚡ GE | Toggle + slider to also include Guild Expeditions in the calculation. At 0.20 (default), 20% of the weight goes to Expeditions and 80% stays with Battlegrounds. |
In the EFF column header of the table you can type a minimum value: typing, say, 80, will show only buildings (or allies) with efficiency above 80, calculated with the current weights. Great for cutting through the noise and seeing only what's actually worth keeping.
A map of the most-used buttons, so you don't have to guess what each icon does.
The Search... box filters by name as you type. If you've typed something and want to start fresh, the ✕ next to the box clears everything in one click. If you delete letters by hand, the search updates instantly, with no delay.
| Filter | What it does |
|---|---|
| Category | Narrows the view to a specific type: Quantum Incursion buildings, ones with ally slots, settlements, Battlegrounds prizes, QI prizes. |
| Event | Shows only buildings tied to a specific in-game event (handy when deciding what to keep from an event that just ended). |
| AND / OR | Decides how multiple active filters combine: AND requires all of them at once, OR needs just one. |
| min EFF | Minimum efficiency threshold (see section 7). |
Several icons in the toolbar toggle groups of columns on or off, keeping the table readable by showing only what you need at that moment: Population, Happiness, Production, Quantum Incursion coins/goods, and the Σ (Sigma) columns that automatically add up General+Battlegrounds (and General+Expeditions, if enabled) so you don't have to do the math in your head.
The checkboxes to the left of each row let you select multiple buildings; the Export button at the top downloads the selected rows as CSV (or all of them, if nothing is selected) — handy if you want to analyze the data elsewhere, like in a spreadsheet.
No. Everything stays in your browser (localStorage). There's no server receiving or storing your game data: if you clear the site's data from your browser, or export it manually with SAVE, you're the only one with a copy.
The game keeps introducing new buildings (especially during events). The database is updated regularly, but a brand-new building might not be mapped yet — in that case the tool still builds a card using the real data it can read from your imported city, even if it's not yet in the general catalog.
Yes, the site is responsive and can even be "installed" as an app on your home screen (both Android and iPhone) for easier access. Keep in mind that importing via the magic wand requires a desktop browser with the FoE Helper extension: on mobile you can still browse data already imported from a saved/loaded profile.
Yes, completely. No account, no subscription, no usage limit.
Feel free to write to [email protected] — I'll reply as soon as I can.