Tool · Encoder comparison

Video Encoder Comparison Report

Built by Raul Vecchione

Here you will find a simulated source video frame and two FFmpeg-transcoded variants of the same video. This simulates the impact you can obtain by tweaking encoder configurations, in this case, the Constant Rate Factor (CRF) by 2 points.

The point is the question, not the codec. The highest-payoff moves are usually small and cheap: one setting, 21% fewer bits, nothing anyone can see. Measure a first move the same way: what it cost, what it returned, whether anyone noticed.

The objective is not to demonstrate a production transcoding setting but the potential impact on bitrate and consequently CDN savings. Subjectively check visual quality vs. bitrate for potential savings. Objective data is also provided below to back improvement statements.

bitrate reduction, CRF 22 vs source: 32.26%bitrate reduction, CRF 22 vs source7817.724 kbps to 5295.443 kbps
PSNR at frame 100: 43.01 dBPSNR at frame 100above the ~40 dB range where differences stop being visible at this size — row 101 of the 150-frame series below, which is 1-indexed
between the two encodes: 1.21 dBbetween the two encodesCRF 20 44.22 dB, CRF 22 43.01 dB

Compare the frames

Comparison View

Wipe

Side-by-side

Wipe view: Move the wipe across a specific area to compare two frames directly and spot compression artifacts or quality differences.

Left frame

Right frame

Wipe position

LeftSource

Codec: h264
Resolution: 1920x1080
Bitrate: 7817.724 kbps
PSNR vs source (frame 100): N/A

Open the 1600px frame

RightCRF 20

Codec: h264
Resolution: 1920x1080
Bitrate: 6686.158 kbps
PSNR vs source (frame 100): 44.22 dB

Open the 1600px frame

Frames are shown at up to 960px wide here and re-encoded near-losslessly for delivery (AVIF quality 92, WebP quality 95) rather than at the aggressive settings used elsewhere on this site, so the artifacts you are judging are the video encoder's and not this page's.

Reveal the measurements

Technical Details

Image	Description	Codec	Resolution	Bitrate (kbps)	Bitrate Difference (vs Source)	Bitrate Difference (vs CRF 20)	PSNR vs Source (Frame 100)	Vision model MOS (1 to 5)
Image 1	Source	h264	1920x1080	7817.724 kbps	N/A	not reported	N/A	4.2
Image 2	CRF 20	h264	1920x1080	6686.158 kbps	-14.47%	N/A	44.22	4.2
Image 3	CRF 22	h264	1920x1080	5295.443 kbps	-32.26%	-20.80%	43.01	4.3

Vision model MOS: a vision language model (gpt-5.5-2026-04-23, run 13 October 2026) scored each frame alone, 1 to 5, without the source or the PSNR. It rated all three about the same. A 0.1 gap from one frame each is not a ranking: the model cannot see the 2 CRF points either. The same pipeline, on three clips: AI video-quality scoring.

Average PSNR Comparison (vs Source)

Comparison	Average PSNR (dB)
Image 2 (CRF 20) vs Image 1 (Source)	46.22
Image 3 (CRF 22) vs Image 1 (Source)	44.52

These are the original report's own averages. The mean of the 150 sampled frames listed below is 46.48 dB and 44.66 dB, so the two are measured over different spans.

Per-Frame PSNR Comparison (vs Source)

PSNR (CRF 20 vs Source)
PSNR (CRF 22 vs Source)

Show all 150 per-frame values

Per-frame PSNR against the source, in decibels
Frame	PSNR, CRF 20 vs source (dB)	PSNR, CRF 22 vs source (dB)
1	50.31	47.4
2	49.21	46.85
3	48.14	46.28
4	48.67	46.6
5	48.66	46.47
6	49.04	46.77
7	48.1	45.77
8	48.54	46.18
9	48.36	45.93
10	48.52	46.08
11	48.29	45.83
12	48.39	45.86
13	47.91	45.42
14	48.8	46.27
15	48.27	45.83
16	48.6	46.17
17	48.04	45.55
18	48.29	45.83
19	48.2	45.75
20	48.41	45.91
21	48.07	45.55
22	48.43	46.06
23	48.26	45.75
24	48.41	45.91
25	48	45.46
26	48.66	46.12
27	48.38	45.85
28	48.61	46.02
29	47.48	44.92
30	48.11	45.72
31	47.89	45.46
32	48.03	45.57
33	47.53	45.01
34	48.11	45.7
35	48.09	45.61
36	48.32	45.88
37	47.5	45.07
38	48.29	45.86
39	47.77	45.45
40	48	45.66
41	47.26	44.91
42	47.99	45.64
43	47.65	45.28
44	47.96	45.58
45	47.2	44.82
46	47.85	45.48
47	47.76	45.58
48	47.91	45.55
49	47.12	44.75
50	47.58	45.3
51	47.24	45.01
52	47.47	45.27
53	47.08	44.86
54	47.85	45.63
55	47.7	45.46
56	47.95	45.64
57	46.65	44.34
58	47.36	45.36
59	46.31	44.68
60	46.51	44.84
61	44.59	43.23
62	46.43	44.78
63	46	44.52
64	46.16	44.6
65	44.32	43.05
66	46.26	44.66
67	45.91	44.44
68	46.03	44.49
69	44.41	43.12
70	46.18	44.56
71	46.18	44.69
72	46.26	44.68
73	44.3	43.1
74	46.59	44.97
75	46.48	44.98
76	46.5	44.98
77	44.46	43.29
78	46.43	44.9
79	46.44	44.98
80	46.28	44.82
81	44.29	43.19
82	46.47	44.93
83	46.39	44.92
84	46.54	44.94
85	43.98	42.85
86	46.21	44.67
87	46.23	44.74
88	46.2	44.65
89	44.48	43.26
90	46.26	44.72
91	46.21	44.71
92	46.21	44.71
93	44.42	43.24
94	46.37	44.79
95	46.2	44.71
96	46.14	44.57
97	44.27	43.09
98	46.31	44.74
99	45.99	44.53
100	46.08	44.55
101	44.22	43.01
102	46.18	44.62
103	45.87	44.44
104	46.07	44.51
105	44.22	43
106	46.15	44.51
107	46.06	44.48
108	46.66	44.84
109	45.96	44.2
110	46.72	44.82
111	46.23	44.47
112	46.28	44.52
113	43.79	42.45
114	45.63	43.98
115	45.33	43.86
116	45.54	43.99
117	43.8	42.46
118	45.72	44.08
119	45.35	43.89
120	45.52	43.95
121	43.74	42.49
122	45.85	44.27
123	45.49	44.03
124	45.81	44.25
125	43.88	42.62
126	45.92	44.35
127	45.63	44.17
128	45.93	44.39
129	44.09	42.83
130	45.98	44.41
131	45.69	44.24
132	45.8	44.27
133	44.02	42.78
134	45.84	44.27
135	45.54	44.03
136	45.71	44.17
137	43.9	42.66
138	45.77	44.2
139	45.43	44.03
140	45.64	44.12
141	43.44	42.24
142	45.24	43.74
143	44.98	43.58
144	45.15	43.65
145	43.58	42.29
146	44.82	43.34
147	44.34	42.97
148	44.79	43.28
149	43.59	42.17
150	43.22	41.8

FFmpeg Resources

Download the following resources to learn more about the FFmpeg commands used in this project:

FFmpeg Commands — Various FFmpeg commands for video processing and analysis
Video Preparation — Commands for preparing videos for PSNR analysis
PSNR Analysis — Commands for performing PSNR analysis on specific frames