If you're staring at a spider in your house and wondering "what spider is this?" — you're not alone. There are over 45,000 spider species worldwide, and the one in your bathroom could be a harmless house spider or, very rarely, something venomous. The fastest way to know for sure is to take a photo and use a spider identifier.

The Easy Way: Identify Your Spider by Picture

Our free AI spider identifier matches your photo against thousands of documented species in under five seconds. You'll get the common name, scientific name, habitat information, and a clear answer to the only question that really matters: is it dangerous?

For the best identification results:

• Photograph the spider from above, showing the body clearly
• Include a common object for scale (a coin, a pen cap)
• Capture the leg pattern and any distinctive markings on the back
• Use good lighting — natural daylight is ideal

Common House Spiders in the United States

American House Spider (Parasteatoda tepidariorum)

Small, round-bodied, brown or grey with a bulbous abdomen. Builds messy cobwebs in corners. Completely harmless and actually eats flies, mosquitoes, and other pests.

Wolf Spider (Lycosidae)

Large, hairy, fast-moving brown or grey spiders that hunt on the ground instead of building webs. Adults can span 1 to 3 inches including legs. Intimidating but not medically dangerous — a bite is similar to a bee sting.

Jumping Spider (Salticidae)

Tiny, compact, fuzzy spiders with huge forward-facing eyes. They hunt by leaping on prey. Curious, friendly, and completely harmless to humans.

Cellar Spider (Pholcidae)

Long, spindly legs with a tiny body. Often called "daddy long-legs." Builds messy webs in basements and ceiling corners. Harmless despite the myth that they are the most venomous spiders on Earth.

Grass Spider / Funnel Weaver

Brown spiders with distinctive sheet-like webs that funnel into a hole. Common in lawns and ground-level vegetation. Bites are rare and mild.

The Two Spiders You Should Actually Worry About

Black Widow (Latrodectus)

Shiny black body with a bright red hourglass marking on the underside of the abdomen. Found in woodpiles, sheds, garages, and outdoor furniture across most of the US. Bite causes intense muscle cramps and requires medical attention, but deaths are rare with modern treatment.

Brown Recluse (Loxosceles reclusa)

Light to medium brown with a distinctive violin-shaped mark on the back just behind the head. Only six eyes (most spiders have eight). Found in the central and southern United States. Bites can cause skin necrosis and need medical evaluation.

How to Tell Them Apart From Look-Alikes

Brown recluses are frequently misidentified. Wolf spiders, grass spiders, and even cellar spiders get mistaken for recluses constantly. The only reliable way to tell is the violin marking and the six-eye pattern (arranged in three pairs). If you're not sure, take a photo and run it through our AI identifier — it's faster than a field guide and far more accurate than guessing.

What to Do If You Find an Unknown Spider

1. Do not touch it. Even harmless spiders may bite defensively.
2. Take a photo. Good lighting, top-down angle, include scale.
3. Identify it. Use our AI identifier or a trusted field guide.
4. Decide what to do. Catch and release harmless spiders outside. Call pest control for confirmed brown recluse or black widow infestations.

Try Our Spider Identifier Now

Upload a photo of the spider you found and get an instant identification, harm assessment, and recommended next steps. It's completely free — identify your spider here.