SimulationCraft WASM
A Free Raidbots Alternative That Runs in Your Browser
Raidbots and this tool run the exact same simulation engine — SimulationCraft. The difference is where the sim runs: their cloud servers with queues and a premium tier, or your own CPU, free, with every feature unlocked.
SimulationCraft WASM compiles the full SimC engine to WebAssembly, so your browser does the number crunching. That one architectural choice removes everything people pay Raidbots Premium for: there is no queue to skip, no iteration cap to lift, and no locked features — because there is no server to protect.
| Feature | SimulationCraft WASM | Raidbots |
|---|---|---|
| Price | Free, all features | Free tier + Premium subscription |
| Queue time | None — starts instantly | Queue on free tier, shorter with Premium |
| Droptimizer | Free (dungeon & raid loot, key level and difficulty aware) | Free with limits; full options need Premium |
| Top Gear equivalent | Gear Compare — bags, vault & loot-table items, free | Top Gear; combination limits on free tier |
| Quick DPS sim | Yes, multithreaded on your CPU | Yes |
| Trinket / item charts | Charts mode, bulk comparison across item levels | Via docs/external sites |
| Import from Armory (no addon) | Yes — region, realm, name | Addon export or login-based import |
| Account required | No | No (free) / Yes (Premium) |
| Where the sim runs | Locally — your profile never leaves the browser | Cloud servers |
| Speed on huge batch sims | Limited by your CPU | Cloud hardware, strong for massive jobs |
| Polish & track record | Newer, actively developed | Years of production hardening |
| Sim engine | Identical — both run SimulationCraft | |
Raidbots vs SimulationCraft: what's the actual difference?
This confuses a lot of players, so let's be precise. SimulationCraft (SimC) is the open-source simulation engine — the thing that models your spec's rotation, talents, trinkets and set bonuses, then runs thousands of virtual fights. Raidbots is a web front-end for that engine: it takes your character, builds a SimC input, runs it on cloud hardware, and shows you the result.
This site is also a front-end for SimC — the same engine version, compiled to WebAssembly so it executes in your browser instead of on a server. That's why comparing "Raidbots vs SimulationCraft accuracy" misses the point: given the same profile and settings, they produce the same numbers. The real comparison is cloud front-end vs local front-end — queue and paywall vs your own silicon.
Free Droptimizer — no premium required
The Droptimizer answers the question that actually decides your week: which boss drops your biggest upgrade? Pick the dungeons or raid difficulties you run, and it sims every relevant drop against your current gear, ranked by DPS gain. Key levels, raid difficulties, and Great Vault item level bumps are all accounted for.
FAQ
Is there a free alternative to Raidbots?
Yes — this one. Same SimulationCraft engine, running locally in your browser via WebAssembly. DPS sims, Droptimizer, gear comparison and trinket charts are all free, with no queue and no account.
Are the results as accurate as Raidbots?
The engine is identical — both tools are front-ends for SimulationCraft. Given the same profile and settings, results agree within the sim's target error. More on precision in stat weights & target error explained.
Can I run a Droptimizer without Raidbots Premium?
Yes. The Droptimizer mode sims every relevant drop from current dungeons and raids and ranks the upgrades, completely free — the computation happens on your CPU.
When is Raidbots the better choice?
Very large batch jobs on a weak device, where cloud hardware beats your CPU, and if you value its years of polish. For everyday gearing decisions on a reasonably modern machine, local simming gives the same answer without the wait.
- How to sim your character — from zero to your first result in a few minutes.
- Free Droptimizer guide — find your biggest upgrade before the raid lockout.
- Great Vault picks — stop guessing which vault item to take.