Brown Recluse vs Cellar Spider
Loxosceles reclusa vs Pholcus phalangioides
These are easy to tell apart once you look at the legs. A cellar spider has thread-thin legs several times the length of a tiny pale body and hangs in a loose web in a ceiling corner. A recluse is a compact, solid-bodied spider on the ground. The cellar spider is harmless.
The one thing that settles it
Leg thickness against body size. A cellar spider's legs are hair-fine and its body is under a centimetre, so the animal looks like a dot with threads attached. A recluse has legs in proportion to a solid body about the size of a small coin. You can see this from across a room, and no photograph is needed.
Side by side
| Character | Brown Recluse | Cellar Spider |
|---|---|---|
| Danger | Dangerous | Harmless |
| Legs | Slender but solid, in proportion to the body. Uniform tan | Extremely long and thread-like, up to a 50 mm span on a tiny body |
| Body | Compact, 6–12 mm, the size of a small coin | Small pale peanut shape, 7–10 mm, looks almost translucent |
| Where it sits | On the ground, in crevices, boxes and folded clothing | Hanging upside-down in a ceiling corner, permanently |
| Web | Flat, irregular, sheet-like, in an undisturbed corner | Loose untidy tangle, always in a high corner |
| When disturbed | Runs and hides | Whirls in the web fast enough to blur, then stops |
| Eyes | Six, in three widely spaced pairs | Eight |
Why they get confused
Mostly by name and by nerves rather than by appearance. Both are pale brownish spiders found indoors, and "long-legged brown spider in the house" is a description that fits either if you have not looked closely. The cellar spider also gets called a daddy long legs, which drags in a separate myth about deadly venom, so people arrive at it already worried.
If you still can’t tell
This is one of the few pairs where a phone photo is usually enough — the leg-to-body proportion is obvious and does not need the eyes resolved. If the spider is hanging upside-down in a ceiling corner, that alone effectively rules out a recluse, which is a ground-level animal that does not hang in webs.
Common questions
Do daddy long legs have the most powerful venom of any spider?
No. It is untrue in both halves: the venom is not exceptionally potent and the fangs are perfectly capable of piercing skin. They have no interest in biting people, and there is no record of one causing harm.
Should I get rid of cellar spiders?
There is a good argument for keeping them. They eat other spiders, including much larger ones, by throwing silk from out of reach. A house with cellar spiders tends to have fewer of everything else.
Is a cellar spider the same as a harvestman?
No, and they are not closely related. A cellar spider is a true spider with two body sections and a web. A harvestman has one oval body, no web, no silk and no venom at all. Both get called daddy long legs.
Full records
- Brown Recluse Dangerous
- Cellar Spider Harmless
Where this was checked
- iNaturalist — Loxosceles reclusa checked 2026-07-30
- iNaturalist — Pholcus phalangioides checked 2026-07-30
- University of California IPM — Spiders checked 2026-07-30
Last reviewed 2026-07-30. We identify, we don’t diagnose — what we can and can’t tell you.