Question 1

What is the difference between resolution and aspect ratio?

Accepted Answer

Resolution is the total pixel count (width × height, e.g. 1920×1080). Aspect ratio is the proportional relationship between width and height (e.g. 16:9). The same resolution can have different aspect ratios and vice versa.

Question 2

What does 4K mean exactly?

Accepted Answer

4K Ultra HD is 3840×2160 pixels (about 8.3 megapixels) at a 16:9 aspect ratio. Cinema 4K (DCI) is 4096×2160. Both are commonly referred to as '4K'.

Question 3

Which resolution should I use for YouTube / TikTok / Instagram?

Accepted Answer

YouTube: 1920×1080 (16:9) or 3840×2160 (4K) for landscape, 1080×1920 (9:16) for Shorts. TikTok & Instagram Reels: 1080×1920 (9:16). Instagram feed: 1080×1080 (1:1) or 1080×1350 (4:5). Use the preset buttons for quick conversion.

Question 4

Is the tool private?

Accepted Answer

Yes. Everything is calculated in your browser. No data is sent to any server.