Brown Recluse Spider vs Black Widow Spider
Quick answer
It is too close to call. The Brown Recluse Spider and the Black Widow Spider are evenly matched on paper, and in the wild the outcome would come down to size, surprise, and circumstance.
This is a hypothetical, educational comparison based on typical size, strength, and natural weaponry. In the wild these animals rarely meet, and most encounters end without a fight.
Invertebrate
Not Evaluated
Invertebrate
Least ConcernBrown Recluse Spider vs Black Widow Spider compared
| Attribute | Brown Recluse Spider | Black Widow Spider |
|---|---|---|
| Weight | 1 g | 1 g |
| Length | 2 cm | 4 cm |
| Top speed | 0.5 km/h | 1.5 km/h |
| Strength | 8/100 | 3/100 |
| Deadliness | 45/100 | 45/100 |
| Intelligence | 15/100 | 6/100 |
| Lifespan | 3 yr | 3 yr |
Brown Recluse Spider vs Black Widow Spider: common questions
Who would win in a fight, a Brown Recluse Spider or a Black Widow Spider?
It is too close to call. The Brown Recluse Spider and the Black Widow Spider are evenly matched on paper, and in the wild the outcome would come down to size, surprise, and circumstance.
Which is bigger, the Brown Recluse Spider or the Black Widow Spider?
The Brown Recluse Spider is heavier, weighing around 0.001 kg compared with the other's 0.001 kg.
Which is faster, the Brown Recluse Spider or the Black Widow Spider?
The Black Widow Spider is faster, reaching about 1.5 km/h versus 0.5 km/h.
Which lives longer, the Brown Recluse Spider or the Black Widow Spider?
The Brown Recluse Spider typically lives longer, up to around 3 years compared with 3 years.
Sources & references
Conservation status follows the IUCN Red List of Threatened Species; size, weight, speed, and lifespan figures are drawn from Animal Diversity Web (University of Michigan Museum of Zoology) and Nowak, Walker’s Mammals of the World (Johns Hopkins University Press), cross-checked against each species’ own guide. Compare full profiles for habitat, diet, and behaviour:
- Brown Recluse Spider — full guide
IUCN Red List (Not Evaluated, Loxosceles reclusa)
- Black Widow Spider — full guide
IUCN Red List (Least Concern, Latrodectus mactans)
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Animal Diversity Web — University of Michigan Museum of Zoology
Life-history, morphology, and measurement data for Brown Recluse Spider and Black Widow Spider.
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Nowak, R. M. (1999). Walker’s Mammals of the World (6th ed.). Johns Hopkins University Press.
Standard reference for body size, weight, and life-span ranges.
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Global Animal Guide editorial standards
How we research, source, and review wildlife comparisons.
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