ID Datasets	Methods	SVHN	TinyImageNet	LSUN	Places	Textures	Average
FPR95(↓)	AUROC(↑)	FPR95(↓)	AUROC(↑)	FPR95(↓)	AUROC(↑)	FPR95(↓)	AUROC(↑)	FPR95(↓)	AUROC(↑)	FPR95(↓)	AUROC(↑)
CIFAR10 (ResNet34)	MSP [7]	61.03	89.01	53.11	85.79	46.79	90.63	43.71	91.88	48.28	90.08	50.58	89.48
ODIN [9]	50.74	92.09	39.82	92.62	33.34	94.17	36.53	93.18	45.00	91.11	41.09	92.63
Energy [5]	42.87	91.20	37.76	92.98	34.25	93.85	38.34	92.44	45.73	90.26	39.79	92.15
Mahalanobis [14]	22.19	93.36	29.35	90.16	25.31	91.89	28.61	91.26	39.34	87.02	28.96	90.74
ReAct [11]	24.60	92.39	33.68	89.71	19.15	93.78	23.69	92.78	32.61	89.27	26.75	91.59
GradNorm [10]	62.47	76.08	73.00	65.21	59.38	72.97	58.93	75.36	67.77	67.41	64.31	71.41
KNN [29]	32.03	95.28	29.56	95.44	27.42	95.92	41.77	93.26	35.41	94.87	33.24	94.95
Rankfeat [15]	84.58	72.99	50.20	89.84	41.63	91.97	67.79	82.64	68.12	80.67	62.46	83.62
ASH-P@70 [30]	23.11	95.53	29.78	93.71	22.72	95.33	25.27	94.35	30.92	93.08	26.36	94.40
GAIA-Z (Ours)	2.47	99.49	6.26	98.63	2.48	99.43	2.27	99.50	2.84	99.36	3.26	99.28
GAIA-A (Ours)	14.44	97.12	16.45	97.07	9.10	98.10	11.06	97.82	12.62	97.54	12.73	97.53
CIFAR10 (WRN40)	MSP [7]	40.51	92.70	50.05	86.99	38.90	91.34	45.41	89.58	56.42	84.57	46.26	89.04
ODIN [9]	16.11	96.91	44.18	89.66	33.37	93.45	40.30	91.31	51.51	87.71	37.09	91.81
Energy [5]	19.94	95.80	41.70	90.04	37.95	91.44	44.88	89.67	55.89	84.58	40.07	90.31
Mahalanobis [14]	21.63	94.99	42.86	89.77	46.87	86.58	45.39	89.47	48.06	88.65	40.96	89.89
ReAct [11]	20.05	95.87	41.32	90.29	37.81	91.57	44.28	89.77	54.88	85.54	39.67	90.61
GradNorm [10]	49.60	80.45	82.23	59.60	78.17	63.55	81.70	59.72	82.93	58.05	74.93	64.27
KNN [29]	27.52	95.55	38.14	93.44	38.95	94.30	45.79	90.65	50.37	90.77	40.16	92.94
Rankfeat [15]	60.02	72.03	72.33	63.24	52.17	83.24	78.43	61.27	86.22	51.97	69.83	66.35
ASH-P@70 [30]	19.94	95.80	41.70	90.04	37.96	91.44	44.53	89.75	55.69	84.71	39.97	90.35
GAIA-Z (Ours)	4.05	99.17	53.31	90.59	12.40	97.92	7.76	98.59	12.30	97.34	17.96	96.72
GAIA-A (Ours)	18.34	96.51	30.98	94.54	12.73	97.70	16.94	96.84	14.93	97.15	18.78	96.55
CIFAR10 (ResNet34)	MSP [7]	86.21	74.13	75.21	79.31	83.58	72.80	87.19	70.60	82.00	74.46	82.84	74.26
ODIN [9]	89.34	70.21	70.00	81.44	83.80	71.37	88.10	67.69	81.81	72.66	82.61	72.67
Energy [5]	87.55	73.91	73.46	79.83	84.38	72.58	88.53	70.17	82.54	74.69	83.29	74.24
Mahalanobis [14]	88.71	73.72	75.70	79.57	88.28	71.63	78.54	79.74	82.63	73.78	81.29	76.16
ReAct [11]	77.53	83.17	71.18	78.60	73.36	84.37	78.41	80.12	72.06	82.54	74.51	81.76
GradNorm [10]	90.70	65.95	80.12	61.44	82.62	58.10	92.29	64.35	85.89	52.48	86.32	60.46
KNN [29]	73.34	80.06	69.24	82.17	76.98	78.36	86.76	71.53	79.95	69.24	77.25	76.27
Rankfeat [15]	92.94	65.55	87.46	74.98	90.84	70.65	90.77	72.68	86.72	73.99	89.75	71.57
ASH-P@65 [30]	81.21	79.46	74.26	81.17	82.84	74.93	85.49	72.91	79.70	77.33	80.70	77.16
GAIA-Z (Ours)	15.73	97.06	63.85	89.17	33.33	94.18	16.78	97.17	15.82	97.09	29.10	94.93
GAIA-A (Ours)	68.02	89.03	68.61	83.33	71.24	86.37	73.15	86.25	63.81	87.12	68.97	86.42
CIFAR10 (WRN40)	MSP [7]	83.44	79.85	76.94	77.84	76.68	80.32	85.81	72.50	83.42	74.94	81.26	77.09
ODIN [9]	80.64	82.34	78.50	76.41	74.43	81.95	84.57	74.58	82.36	76.51	80.10	78.36
Energy [5]	84.58	79.72	76.77	77.90	76.32	80.45	86.13	72.35	83.95	74.83	81.55	77.05
Mahalanobis [14]	82.36	81.07	82.95	79.20	74.76	81.16	82.44	76.06	83.72	76.93	80.97	78.34
ReAct [11]	75.04	82.36	76.09	75.83	66.64	83.06	77.94	78.18	77.66	78.33	74.67	79.55
GradNorm [10]	85.27	69.22	86.58	67.75	81.10	62.38	87.01	52.89	89.41	51.30	85.89	60.71
KNN [29]	46.88	88.97	70.88	82.86	68.92	76.83	83.57	69.64	60.41	83.66	66.13	80.39
Rankfeat [15]	80.39	77.10	94.58	52.35	91.63	61.89	86.83	67.71	88.00	67.36	88.29	65.28
ASH-P@70 [30]	81.20	80.99	76.24	77.92	74.78	81.06	84.81	73.78	81.97	76.12	79.80	77.97
GAIA-Z (Ours)	15.19	97.19	87.06	73.42	37.97	91.59	25.64	95.26	27.29	94.05	38.63	90.30
GAIA-A (Ours)	35.49	93.60	53.37	89.86	33.52	93.86	27.62	95.37	31.44	94.16	36.29	93.37