Blog header images with AI: ratio, title space, a steady look and light files

A blog header does one small job: it tells a reader, in half a second, what kind of place this is. Then it gets cropped by a card, a social preview and a phone screen, and has a title laid over it. Most weak headers are not ugly. They were made without any of that in mind. Here is the order I work in, from the frame to the file.

1. Start with the widest frame you will need

Most blog themes show a header at 16:9 or close to it, so that is the ratio to pick in the studio's Ratio picker before the first render. The price does not depend on the frame, only on the model and quality, so there is no saving in guessing small. Rendering wide and cropping later works; rendering square and stretching does not, because the missing sides do not exist. The aspect ratio guide covers the other frames if your theme is unusual.

Write the scene for a wide shape too. Things that run sideways suit it: a shoreline, a desk, a row of objects. A single tall subject in a wide frame leaves two big empty sides, which is sometimes exactly what you want and sometimes a waste.

2. Leave room for the title

If your theme puts the title over the picture, the picture needs a calm area. If it puts the title underneath, you can skip this step and use the whole frame. Either way, decide before you prompt. The space for text post goes into the long version; the short one is to name the empty area and what it is made of, and to place the subject on the opposite side.

Dark and quiet areas are the easiest to write over, since light letters on a dark field stay readable even if the render has a little texture. A pale area works too, but any stray shape in it shows up behind dark letters at once.

3. Keep one look across the blog

A blog index is a grid of headers seen together, and that is where inconsistency hurts. Pick a small recipe and reuse it word for word: the same kind of subject (one object, one setting), the same light, a two-colour palette, the same camera distance. Keep the recipe as a text file and change only the subject line per post.

• Subject rule: one object per header, never a crowd.
• Light: one named source and one named colour, for example a low warm lamp.
• Palette: two colours, written into every prompt.
• Framing: the same side for the subject, the same empty side for the title.

For the first few headers, attach your favourite one as a reference so the next render inherits its mood. The reference images post explains how strongly a reference holds and where it stops holding. Use the same model for the whole blog as well: two models read the same words differently, and the difference shows in a grid. Still is a sensible default, from €0.40 a render, and Still Lite from €0.30 is enough for trying compositions before you spend on the final.

4. Check the crops before you publish

One header becomes several shapes: the wide hero, a card thumbnail that is often closer to square, and a social preview. Test the worst one. Crop the finished image to a square from the middle and ask whether the subject survives. If the subject sits at the far right, the square will cut it, so keep it within the middle two thirds, or plan a second render in a squarer frame for the card.

5. Keep the file weight sane

The studio gives you a picture at up to 2K, which is more than a page header usually needs. A header that shows at the width of a content column does not have to be shipped at full size; scaling it to about twice its displayed width keeps it sharp on dense screens. Then save it in a modern web format at a moderate quality in your own editor. Smooth gradients, such as a dark violet wall, are where heavy compression shows first as visible bands, so check the dark area at full size after you compress.

A calm, low-detail header is also lighter on the wire than a busy one, because there is less detail to store. The picture that is good for the title is good for the page speed too. If you need the opposite, a larger version of a render you already like, the upscaler post explains when to use it.

What the studio cannot do here

It does not crop, resize or compress for you, and it has no template that puts a title on the picture: you do that in your own tools. It cannot guarantee that a quiet area stays empty, so some renders will need a re-roll. And it cannot promise that ten headers made over ten weeks match perfectly; a written recipe and a reference get you close, not identical. If your brand needs exact colours, grade the set in your editor.

Open the studio and render three headers with the same recipe. Put them side by side before you commit. For a different style, browse the image models on the models page; the thumbnails and cover art post covers the sibling job of small preview images.