How to make a YouTube thumbnail, free

Start at the right canvas size

Open the editor and set the size before you do anything else. Composing at the wrong shape and cropping later is what kills good designs, because the crop always takes the edges and the edges are where people put text.

For a normal video you want 16:9. YouTube's own documentation gives a recommended resolution of 3840 x 2160, a minimum width of 640 pixels, JPG or PNG, and a file size limit that depends on where you upload from: 2 MB from the mobile app, up to 50 MB from a desktop browser.

If you only ever pick one size, 1920 x 1080 is the pragmatic choice. It is double the linear resolution of the old 1280 x 720 standard, it stays small enough to upload from a phone as a JPG, and it has enough pixels for a 4K television home screen not to look soft.

Get a background that is not fighting you

Two things work. A photograph or screenshot with a clear, uncluttered area for your text, or a flat bold colour with nothing on it at all. What does not work is a busy photograph with text dropped anywhere on top, because the text edges dissolve into the detail behind them.

Drop the image in and look at where the quiet areas are. That is where the words go. If there is no quiet area, either darken part of the image or use a solid shape behind the text. Both are one control in the editor and both are better than hoping.

Cut the subject out if there is a person

A person cut out of their background and placed over a bold colour is the most copied composition on YouTube, and it is copied because it works: it separates the face from everything else, and faces are what the eye finds first.

The cut-out tool does this without uploading anything. What separates a good cut-out from an obvious one is the edge. Zoom in on the hair. If there is a halo of the old background still attached, the erase brush removes it in a few strokes. If the tool has eaten part of a shoulder, the restore brush puts it back.

Then add a thin outline or a soft glow behind the cut-out. That is the step almost everyone skips, and it is what stops the person looking pasted on.

Three words, not seven

The single most common mistake is writing a sentence. The thumbnail is not where the story goes; the title underneath is. The thumbnail carries the hook, and a hook that takes longer than half a second to read has already lost.

Three or four words is the working limit. Set them in a heavy condensed typeface, make them big enough that they occupy a real share of the frame, and give them a thick dark outline so they hold up against any background.

Say something the title does not. If the title is the claim, the thumbnail is the reaction. Repeating the title word for word wastes the only other piece of space you get.

Keep everything out of the corners

YouTube draws its own interface on top of your image. The video duration sits in a dark rounded box in the bottom-right corner on nearly every surface where videos are listed, and once someone has partly watched, a red progress bar runs along the bottom edge.

The habit that avoids all of it: keep every element that carries meaning inside the central 90 per cent of the frame. That leaves a 5 per cent margin on all four sides, which absorbs the badge, the bar and the edge cropping that some surfaces apply.

The editor draws that zone over your design when you switch it on, so you can see what is at risk instead of estimating.

Check it small before you check it big

This is the step that changes results. Your design looks magnificent at 1280 pixels wide on a monitor. It will be shown at roughly the width of a thumb on a phone. Those are different images.

The preview panel beside the canvas shows it at the real displayed size, in a mock feed, next to the sort of surroundings it will actually sit in. If you cannot read your own text there, nobody will read it on the home page either.

The readability score does the same check numerically: it measures the contrast between your text and whatever is behind it, checks the type size relative to the frame, and warns you when something important is sitting under the duration badge.

Export the right file

PNG when the design is flat colour and hard-edged text; it stays crisp and has no compression artefacts around letters. JPG when the design is mostly photographic and you need the file small, which is the case when you upload from a phone.

Whatever you send, YouTube re-encodes it and generates its own set of derivatives. That second lossy pass is why a heavily compressed JPG looks worse on YouTube than it did on your desktop. Give the encoder a clean, lightly compressed source and it survives the trip.

There is no watermark, no account and no export limit, so make three versions and pick the one that reads best small.