What it costs to run WFSim, and where to chip in. WFSim is a free, open-source Warframe calculator, AGPL-3.0. A donation covers the domain, the CDN and the measurement work — it buys no feature and no perk.
Every formula cites its source, and every golden test is calibrated against a real in-game run.Why you can check it
Warframes
Operator
Companions
Weapons
Support WFSim
A Warframe calculator built to match in-game measurements, item by item. Building, simulating and optimizing are the whole of it, and they are the same for everyone.
It does not score an opening state. It runs the engagement — every ramp, every reload, every status that had to land before the damage depending on it — and reports what happened.
How it works
How much of a grenade's damage was the impact and how much was the cloud it left behind is something the fight works out. It is not a ratio you type in.
A mod that stacks on kill starts the fight at zero stacks. It builds during the fight, expires, and decays — so the build's own numbers change while you are shooting.
How many Forma a build needs is computed, and so is whether it fits in the weapon at all.
Why you can check it
Every formula in the engine cites its source — a wiki page, a datamine, or a measurement — and every golden test is calibrated against a real in-game run.
It tells you what it cannot model, on the card where you are standing: on a weapon, an evolution, a mod, an arcane, an enemy. It lists those itself rather than waiting to be asked.
Sometimes it says the number is right and the game is wrong, and names the bug a hotfix would take away.
And if your own in-game measurement disagrees with it, the measurement wins. That is a bug report about reality, and it is the one thing that changes what this engine does.
Chip in
One coffee is enough, and it is not a smaller version of anything — there is no target here and no total to fill. Give once, or monthly if you would rather.
An in-game measurement is the only thing that changes what the engine does, and it wins whoever reports it — so the way to move a number here is to go and measure one.
Building, simulating and optimizing are the same for everyone, and what guarantees that is not me: this is AGPL-3.0, so the engine, the game data and the wasm are public and you can run your own copy.
A fix to the builder, the simulator or the optimizer ships to everybody at once. There is no earlier copy.
There are no recommended builds here and no curated list. Every row on the board is what this engine computed under the benchmark's own pinned terms, so anyone with the repository reproduces the same number.
What you have run here stays in your own browser and is sent nowhere. The only place a visit is counted at all is Cloudflare's own request log, which is what serves the page.
Supporting this buys no priority: not over what gets built next, not in the queue, not on a reply. I will read your message knowing you backed this, and it would be dishonest to claim that changes nothing — but that is a courtesy, not an obligation, and it is the whole of what it is.
Where it goes
The wfsim.app domain, and its renewal — the one bill that arrives whether anybody visits or not.
Serving this site costs nothing, and that is worth saying plainly: Cloudflare does not meter what it hands out, so the pages, the art and the board are free however many of you turn up. What is metered is the update channel behind the Windows client, billed by the byte every time a copy updates itself.
Time, which is most of it: new weapons, new mechanics, and the hours in the game that every calibrated number is measured against.
Free, and worth more
Report a number that disagrees with your own in-game measurement. That is the one contribution nothing else can replace — every formula here is calibrated against a real run, and a discrepancy is a bug report on reality.GitHub Issues · QQ group · Discord
Star the repository, or send a build link to someone who is still doing this by hand.github.com/magenie33/wfsim
Chipping in is a gift rather than a purchase — it covers what this site costs to run, and it buys nobody an advantage.
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Benchmark
Forma plan your rules, and the builds that share these polarities
0
Parts
0
Wielder
1
Mode
2
Mods
0 / 00 Forma
Stance
A stance decides what the weapon actually swings: it publishes a combo per mode, and installing one replaces the weapon's own. It also GRANTS capacity instead of costing it — 10 on a slot of its own polarity, 5 on a bare one, 4 on the wrong colour.
Exilus
A polarity can be swapped between this slot and a main one — the slot stays Exilus. So its polarity counts toward any build, even one that leaves it empty.
3
Arcane
4
Evolution
Incarnon Genesis
5
Valence
Σ
Stats
≡
Build
▶
Sim
1 · The fight who you are shooting at, where, and for how long
2 · External bonuses what the wielder is doing, and what others hand them — a ticked number replaces the wielder's own
3 · Limits what this run is allowed to assume
4 · Buffs the stacks the run STARTS with — the fight still grants and decays them on their own triggers
5 · Extra stats anything this weapon is handed from outside its build — it lands in the same bucket a mod would
6 · Warframe buffs abilities cast on this weapon — set your Ability Strength and the values follow
7 · Measure what to read off the run — the scenario's own term, so an official ruler pins it
The whole fight — every field, including the ones this weapon hides
Σ
Result
φ
Shapley analysis
what each part multiplies the result by
4
Rivens
All rivens every riven you have made for this weapon, with what it actually rolls
5
Enemies
All targets every enemy you have made — pick one in the simulator's target list like any other
⚙
The search
the starts and the limits — what a search preset saves, with the runs per candidate
① Starts
② Limits none by default — click an option to exclude it; a start that pins an excluded option cannot run, one that only holds it has it replaced
▶
The fight
the simulator's — every candidate is scored under it, and it is edited over there
★
Optimize
each start improved by the quick calc until nothing helps
—
Forma plan your rules, and the builds that share these polarities
1
Mods
0 / 00 Forma
Aura
An aura hands capacity back instead of costing it: twice its drain on its own polarity, 80% of it rounded down on another. A polarity moves between all ten slots, the aura's included.
Exilus
2
Arcanes
3
Archon Shards
4
Operator
Σ
Stats
5
Abilities
—
1
Mods
0 / 00 Forma
Nothing a companion seats moves a weapon's numbers yet: no robotic weapon reads its wielder's stats, and no precept is run. What this answers is capacity and Forma.
Operator
Only the active school's nodes apply. A node that needs an Operator action counts only when you say it is running.