WebP benchmark: web lossless optimization

last updated: 20/07/2023

this test shows how PNG to WebP converters use automatic lossless reductions for web usage by using the default or the same command — point is to highlight heuristics and transforms. evaluations are done on specific image test sets

as the process is run with the default (or same) command, it would be possible for some tools to achieve 'better' result with specific flags for some files (but not always)
speed is measured file per file, with and without mt if significant — this would not be representative of the maximum speed if the tool handle (or was built in mind with) mp
top score on one image set does not mean the tool always outperforms other

PNG: all are 8 bits/sample — or 1, 2, 4, 8 bits/pixels for paletted, critical chunks only
MAC: Intel(R) Core(TM) i5-12400 (6C, 12T), 2.50 GHz — 16,0 Go DDR4 RAM — WD Black SN750 1 To — Windows 11 Pro
NTE: this document is generated automatically without any human verification

you can sort results (test, time (s), saved (MB)) — ascending/descending with javascript enabled
you can see details by clicking on each image test sets

tools

tool	version
cwebp.exe	1.3.1
pingo.exe	1.07

results

alpha - files

test	time (s)	saved (MB)
cwebp -z 6	2.66	4.093
cwebp -z 8	3.89	4.125
cwebp -z 9	34.97	4.171
cwebp -z 9 -mt	19.89	4.171
pingo -s0 -l	2.67	4.105
pingo -s1 -l	3.31	4.106
pingo -s2 -l	4.42	4.135
pingo -s3 -l	4.68	4.138
pingo -s3 -l (mt)	4.52	4.138
pingo -s4 -l	4.71	4.138
pingo -s4 -l (mt)	4.50	4.138

bitdepth-4 - files

test	time (s)	saved (MB)
cwebp -z 6	0.49	0.166
cwebp -z 8	1.38	0.168
cwebp -z 9	12.59	0.173
cwebp -z 9 -mt	9.19	0.173
pingo -s0 -l	0.66	0.166
pingo -s1 -l	0.79	0.166
pingo -s2 -l	1.07	0.167
pingo -s3 -l	1.56	0.170
pingo -s3 -l (mt)	1.38	0.170
pingo -s4 -l	1.62	0.170
pingo -s4 -l (mt)	1.39	0.170

bitdepth-8 - files

test	time (s)	saved (MB)
cwebp -z 6	1.24	0.245
cwebp -z 8	3.32	0.245
cwebp -z 9	35.61	0.265
cwebp -z 9 -mt	26.66	0.265
pingo -s0 -l	1.66	0.236
pingo -s1 -l	1.74	0.244
pingo -s2 -l	2.51	0.245
pingo -s3 -l	3.91	0.250
pingo -s3 -l (mt)	3.40	0.250
pingo -s4 -l	4.15	0.250
pingo -s4 -l (mt)	3.42	0.250

colortype-0 - files

test	time (s)	saved (MB)
cwebp -z 6	4.09	1.350
cwebp -z 8	5.12	1.399
cwebp -z 9	74.90	1.440
cwebp -z 9 -mt	46.00	1.440
pingo -s0 -l	4.04	1.343
pingo -s1 -l	5.53	1.349
pingo -s2 -l	7.81	1.410
pingo -s3 -l	8.64	1.424
pingo -s3 -l (mt)	8.02	1.426
pingo -s4 -l	8.53	1.424
pingo -s4 -l (mt)	8.02	1.426

colortype-2 - files

test	time (s)	saved (MB)
cwebp -z 6	6.82	5.797
cwebp -z 8	7.97	5.813
cwebp -z 9	73.02	5.906
cwebp -z 9 -mt	43.42	5.906
pingo -s0 -l	7.17	5.780
pingo -s1 -l	7.78	5.790
pingo -s2 -l	8.49	5.798
pingo -s3 -l	8.51	5.801
pingo -s3 -l (mt)	8.53	5.804
pingo -s4 -l	9.16	5.808
pingo -s4 -l (mt)	9.10	5.812

colortype-3 - files

test	time (s)	saved (MB)
cwebp -z 6	3.69	0.511
cwebp -z 8	8.03	0.564
cwebp -z 9	113.16	0.788
cwebp -z 9 -mt	80.77	0.788
pingo -s0 -l	5.05	0.749
pingo -s1 -l	6.00	0.782
pingo -s2 -l	7.98	0.799
pingo -s3 -l	13.31	0.844
pingo -s3 -l (mt)	10.79	0.845
pingo -s4 -l	14.19	0.846
pingo -s4 -l (mt)	10.85	0.847

colortype-4 - files

test	time (s)	saved (MB)
cwebp -z 6	5.67	2.700
cwebp -z 8	6.46	2.721
cwebp -z 9	68.08	2.757
cwebp -z 9 -mt	44.02	2.757
pingo -s0 -l	5.65	2.701
pingo -s1 -l	6.15	2.711
pingo -s2 -l	6.96	2.718
pingo -s3 -l	6.85	2.723
pingo -s3 -l (mt)	6.95	2.723
pingo -s4 -l	11.14	2.724
pingo -s4 -l (mt)	9.76	2.724

colortype-6 - files

test	time (s)	saved (MB)
cwebp -z 6	7.84	7.107
cwebp -z 8	9.80	7.215
cwebp -z 9	87.78	7.327
cwebp -z 9 -mt	50.02	7.327
pingo -s0 -l	8.39	7.104
pingo -s1 -l	9.15	7.127
pingo -s2 -l	10.95	7.207
pingo -s3 -l	10.90	7.210
pingo -s3 -l (mt)	10.79	7.210
pingo -s4 -l	13.45	7.213
pingo -s4 -l (mt)	13.03	7.213

filter - files

test	time (s)	saved (MB)
cwebp -z 6	3.04	1.442
cwebp -z 8	4.95	1.485
cwebp -z 9	31.90	1.502
cwebp -z 9 -mt	17.19	1.502
pingo -s0 -l	3.06	1.438
pingo -s1 -l	3.65	1.446
pingo -s2 -l	5.37	1.487
pingo -s3 -l	5.37	1.487
pingo -s3 -l (mt)	5.43	1.487
pingo -s4 -l	6.60	1.490
pingo -s4 -l (mt)	6.34	1.490

content-chart - files

test	time (s)	saved (MB)
cwebp -z 6	1.73	1.384
cwebp -z 8	2.46	1.389
cwebp -z 9	56.43	1.423
cwebp -z 9 -mt	31.29	1.423
pingo -s0 -l	1.80	1.381
pingo -s1 -l	2.22	1.384
pingo -s2 -l	2.65	1.388
pingo -s3 -l	2.63	1.388
pingo -s3 -l (mt)	2.67	1.388
pingo -s4 -l	2.68	1.389
pingo -s4 -l (mt)	2.63	1.389

content-flat - files

test	time (s)	saved (MB)
cwebp -z 6	1.53	1.724
cwebp -z 8	2.03	1.725
cwebp -z 9	14.00	1.743
cwebp -z 9 -mt	7.89	1.743
pingo -s0 -l	1.60	1.723
pingo -s1 -l	2.66	1.720
pingo -s2 -l	2.66	1.721
pingo -s3 -l	2.73	1.721
pingo -s3 -l (mt)	2.68	1.721
pingo -s4 -l	3.02	1.720
pingo -s4 -l (mt)	2.87	1.720

content-gradient - files

test	time (s)	saved (MB)
cwebp -z 6	1.58	4.218
cwebp -z 8	1.84	4.216
cwebp -z 9	16.32	4.217
cwebp -z 9 -mt	10.17	4.217
pingo -s0 -l	1.46	4.217
pingo -s1 -l	1.82	4.170
pingo -s2 -l	2.25	4.166
pingo -s3 -l	2.59	4.166
pingo -s3 -l (mt)	2.20	4.166
pingo -s4 -l	2.74	4.166
pingo -s4 -l (mt)	2.34	4.166

content-icons-gradient - files

test	time (s)	saved (MB)
cwebp -z 6	1.41	1.469
cwebp -z 8	1.97	1.484
cwebp -z 9	22.22	1.510
cwebp -z 9 -mt	11.87	1.510
pingo -s0 -l	1.47	1.469
pingo -s1 -l	1.72	1.478
pingo -s2 -l	2.23	1.484
pingo -s3 -l	2.10	1.484
pingo -s3 -l (mt)	2.12	1.484
pingo -s4 -l	2.21	1.482
pingo -s4 -l (mt)	2.24	1.482

content-icons-realistic - files

test	time (s)	saved (MB)
cwebp -z 6	1.69	2.349
cwebp -z 8	2.63	2.405
cwebp -z 9	29.06	2.415
cwebp -z 9 -mt	15.29	2.415
pingo -s0 -l	1.75	2.347
pingo -s1 -l	2.15	2.374
pingo -s2 -l	2.83	2.405
pingo -s3 -l	2.86	2.405
pingo -s3 -l (mt)	2.78	2.405
pingo -s4 -l	2.85	2.405
pingo -s4 -l (mt)	2.88	2.405

content-icons-small - files

test	time (s)	saved (MB)
cwebp -z 6	3.55	1.268
cwebp -z 8	4.32	1.282
cwebp -z 9	44.13	1.331
cwebp -z 9 -mt	24.61	1.331
pingo -s0 -l	3.66	1.270
pingo -s1 -l	4.32	1.282
pingo -s2 -l	4.50	1.281
pingo -s3 -l	4.61	1.281
pingo -s3 -l (mt)	4.77	1.281
pingo -s4 -l	6.75	1.293
pingo -s4 -l (mt)	6.75	1.293

content-icons-small-palette - files

test	time (s)	saved (MB)
cwebp -z 6	3.16	0.244
cwebp -z 8	4.89	0.258
cwebp -z 9	64.98	0.309
cwebp -z 9 -mt	48.13	0.309
pingo -s0 -l	4.86	0.310
pingo -s1 -l	6.28	0.315
pingo -s2 -l	6.59	0.317
pingo -s3 -l	7.73	0.321
pingo -s3 -l (mt)	7.12	0.321
pingo -s4 -l	8.17	0.322
pingo -s4 -l (mt)	7.21	0.322

content-icons-very-small - files

test	time (s)	saved (MB)
cwebp -z 6	2.10	0.143
cwebp -z 8	2.51	0.144
cwebp -z 9	10.97	0.146
cwebp -z 9 -mt	8.75	0.146
pingo -s0 -l	2.26	0.137
pingo -s1 -l	2.41	0.137
pingo -s2 -l	2.47	0.136
pingo -s3 -l	2.64	0.136
pingo -s3 -l (mt)	2.73	0.136
pingo -s4 -l	2.66	0.136
pingo -s4 -l (mt)	2.75	0.136

content-low-colors - files

test	time (s)	saved (MB)
cwebp -z 6	8.04	3.639
cwebp -z 8	11.77	3.665
cwebp -z 9	95.91	7.052
cwebp -z 9 -mt	53.26	7.052
pingo -s0 -l	5.83	6.929
pingo -s1 -l	7.20	6.929
pingo -s2 -l	11.49	6.978
pingo -s3 -l	11.83	6.983
pingo -s3 -l (mt)	11.65	6.985
pingo -s4 -l	11.84	6.983
pingo -s4 -l (mt)	11.70	6.985

content-palettes - files

test	time (s)	saved (MB)
cwebp -z 6	13.74	3.964
cwebp -z 8	30.73	4.545
cwebp -z 9	529.84	5.397
cwebp -z 9 -mt	366.22	5.397
pingo -s0 -l	17.46	5.013
pingo -s1 -l	22.92	5.173
pingo -s2 -l	35.51	5.248
pingo -s3 -l	52.66	5.474
pingo -s3 -l (mt)	43.63	5.502
pingo -s4 -l	54.70	5.482
pingo -s4 -l (mt)	43.90	5.510

content-palettes-big - files

test	time (s)	saved (MB)
cwebp -z 6	1.60	0.162
cwebp -z 8	6.04	0.325
cwebp -z 9	35.75	0.435
cwebp -z 9 -mt	22.78	0.435
pingo -s0 -l	1.64	0.534
pingo -s1 -l	3.27	0.564
pingo -s2 -l	3.52	0.566
pingo -s3 -l	4.51	0.573
pingo -s3 -l (mt)	3.67	0.573
pingo -s4 -l	4.74	0.602
pingo -s4 -l (mt)	3.69	0.602

content-pics - files

test	time (s)	saved (MB)
cwebp -z 6	5.49	6.708
cwebp -z 8	11.10	6.867
cwebp -z 9	112.12	7.176
cwebp -z 9 -mt	61.44	7.176
pingo -s0 -l	6.12	6.888
pingo -s1 -l	6.90	6.892
pingo -s2 -l	9.20	6.964
pingo -s3 -l	10.18	6.976
pingo -s3 -l (mt)	10.23	6.976
pingo -s4 -l	12.57	7.015
pingo -s4 -l (mt)	12.60	7.015

content-pics-grayscale - files

test	time (s)	saved (MB)
cwebp -z 6	4.69	3.229
cwebp -z 8	7.41	3.322
cwebp -z 9	87.06	3.323
cwebp -z 9 -mt	47.97	3.323
pingo -s0 -l	5.11	3.206
pingo -s1 -l	6.06	3.196
pingo -s2 -l	6.95	3.209
pingo -s3 -l	8.43	3.197
pingo -s3 -l (mt)	8.39	3.197
pingo -s4 -l	12.23	3.169
pingo -s4 -l (mt)	12.21	3.169

content-screenshots - files

test	time (s)	saved (MB)
cwebp -z 6	1.62	1.111
cwebp -z 8	3.10	1.128
cwebp -z 9	15.56	1.149
cwebp -z 9 -mt	8.76	1.149
pingo -s0 -l	1.61	1.097
pingo -s1 -l	1.88	1.103
pingo -s2 -l	3.03	1.117
pingo -s3 -l	3.06	1.117
pingo -s3 -l (mt)	3.06	1.117
pingo -s4 -l	3.43	1.128
pingo -s4 -l (mt)	3.26	1.128

content-sprites - files

test	time (s)	saved (MB)
cwebp -z 6	1.14	1.642
cwebp -z 8	2.46	1.648
cwebp -z 9	40.58	1.659
cwebp -z 9 -mt	27.12	1.659
pingo -s0 -l	1.34	1.647
pingo -s1 -l	1.51	1.650
pingo -s2 -l	2.16	1.652
pingo -s3 -l	3.54	1.658
pingo -s3 -l (mt)	3.12	1.658
pingo -s4 -l	3.47	1.658
pingo -s4 -l (mt)	3.13	1.658

content-text - files

test	time (s)	saved (MB)
cwebp -z 6	1.27	0.943
cwebp -z 8	2.65	0.957
cwebp -z 9	46.23	0.973
cwebp -z 9 -mt	29.85	0.973
pingo -s0 -l	1.22	0.882
pingo -s1 -l	1.69	0.931
pingo -s2 -l	2.93	0.945
pingo -s3 -l	2.91	0.950
pingo -s3 -l (mt)	2.97	0.933
pingo -s4 -l	3.49	0.921
pingo -s4 -l (mt)	3.47	0.905

ordered-transform-2 - files

test	time (s)	saved (MB)
cwebp -z 6	7.54	2.914
cwebp -z 8	9.36	2.991
cwebp -z 9	73.93	3.088
cwebp -z 9 -mt	44.57	3.088
pingo -s0 -l	8.02	2.910
pingo -s1 -l	8.97	2.968
pingo -s2 -l	10.15	2.996
pingo -s3 -l	10.28	2.996
pingo -s3 -l (mt)	10.20	2.996
pingo -s4 -l	11.79	3.006
pingo -s4 -l (mt)	11.74	3.006

ordered-transform-4 - files

test	time (s)	saved (MB)
cwebp -z 6	4.24	11.917
cwebp -z 8	7.76	12.059
cwebp -z 9	108.70	12.454
cwebp -z 9 -mt	78.46	12.454
pingo -s0 -l	5.38	12.491
pingo -s1 -l	6.45	12.533
pingo -s2 -l	9.68	12.428
pingo -s3 -l	12.43	12.470
pingo -s3 -l (mt)	9.73	12.471
pingo -s4 -l	12.02	12.470
pingo -s4 -l (mt)	9.44	12.471

ordered-transform-6 - files

test	time (s)	saved (MB)
cwebp -z 6	4.14	2.006
cwebp -z 8	7.85	2.182
cwebp -z 9	108.27	2.534
cwebp -z 9 -mt	75.95	2.534
pingo -s0 -l	5.36	2.545
pingo -s1 -l	6.39	2.586
pingo -s2 -l	9.51	2.502
pingo -s3 -l	12.31	2.541
pingo -s3 -l (mt)	9.52	2.541
pingo -s4 -l	12.50	2.541
pingo -s4 -l (mt)	9.59	2.541

reductions - files

test	time (s)	saved (MB)
cwebp -z 6	6.50	6.821
cwebp -z 8	13.06	6.951
cwebp -z 9	138.93	7.245
cwebp -z 9 -mt	90.33	7.245
pingo -s0 -l	6.97	7.045
pingo -s1 -l	9.35	7.168
pingo -s2 -l	11.92	7.208
pingo -s3 -l	15.39	7.239
pingo -s3 -l (mt)	13.95	7.239
pingo -s4 -l	17.80	7.240
pingo -s4 -l (mt)	15.25	7.240