Guides
Notes from converting the same source files ourselves: audio, video and image formats, audio cutting, app icon sizes and thumbnail ratios, with size, quality and time measured.
MP3 vs OGG (Opus) vs WAV: we converted speech and musicSpeech kept its whole voice band at OGG 64 kbps, while MP3 128 kbps cut music above 16 kHz. Compared with spectrograms and size tables.
Cutting MP3 and WAV: we measured where each format really starts and endsWAV and OGG started exactly where the source did, while MP3 started 25.1 ms late and turned a 10 s range into 10.031 s. Start-position, fade and join figures plus settings by use.
MP4 vs WEBM vs MOV vs GIF: we converted a 10-second clipMP4 Standard was 15.7% of the source, while a 480 px GIF was 5.7 times larger than MP4. Size, conversion time and quality by format.
PNG vs JPEG vs WEBP: we converted a photo, a screenshot and a logoFor photos, WEBP 85% was 38% smaller than JPEG at the same setting; a transparent logo got a white box as JPEG. Compared with zooms and PSNR.
App icon sizes and safe zones: we generated 74 files from two iconsThe detailed icon blurred from 58 px, and artwork with its own background left a square edge as an Android adaptive foreground.
Thumbnail ratios and cropping: we cut a 16:9 thumbnail to 1:1, 4:5 and 9:16Centre crops cut off the title on the left. Crop coordinates by ratio, file size by format and YouTube's current recommendations.