WordPress Media Settings: Prepare Images Optimally for Web, SEO and Performance

WordPress Media Settings: Prepare Images Optimally for Web, SEO and Performance

The media settings in WordPress determine how your website handles uploaded images and files. A clean configuration is especially important for images because they often make up the largest share of a website’s data volume. Unoptimised images can consume storage space, increase backup sizes and worsen your website’s loading time.

When an image is uploaded, WordPress automatically creates several image sizes. This allows your website to use smaller or larger variants depending on the layout, instead of always delivering the original image. When the media settings, theme and actual image usage work well together, visitors benefit from faster loading times and a better user experience.

Where can you find the media settings?

You can find the media settings in the WordPress dashboard under:

Settings > Media

There you can define the default sizes for uploaded images. Depending on the WordPress version and theme, you will see settings for thumbnails, medium image sizes, large image sizes and the organisation of uploads in month- and year-based folders.

Important: These settings mainly affect newly uploaded images. Existing images are not automatically recalculated when the media settings are changed. Additional tools or plugins for regenerating thumbnails are required for this.

1. What happens when an image is uploaded?

When you upload an image to the WordPress media library, WordPress normally does not only store the original image. Several smaller variants are also created automatically. These variants are used depending on where the image appears, for example as a thumbnail, in posts, in galleries, in widgets or on archive pages.

Typical image sizes are:

• Thumbnail: Small display for overviews, galleries or post lists.
• Medium size: Suitable for images within text or smaller content areas.
• Large size: For wider content areas or larger displays.
• Original image: The uploaded original file, provided WordPress does not scale it automatically.
• Theme-specific sizes: Many themes and plugins additionally generate their own image sizes.

This automatic creation is generally useful. It prevents, for example, a small thumbnail from being loaded as a huge original file.

2. Set thumbnails correctly

Thumbnails are often used in post overviews, galleries, widgets or related posts. In the media settings, you can define the width and height of thumbnails.

A common setting is a square thumbnail, for example 150 × 150 pixels. Depending on the theme, however, a different format may also be useful. Modern themes often use wider preview formats, for example for blog cards or post lists.

Therefore, check:

• How does your theme display featured images in overviews?
• Are images displayed square or in landscape format?
• Are faces or important parts of the image cut off?
• Are thumbnails sharp enough on mobile devices?
• Does your theme generate its own thumbnail sizes?

3. Choose a sensible medium image size

The medium image size is often used for images embedded within a post or page. This size should match your content area.

For example, if your content area is about 800 pixels wide, there is little benefit in embedding much larger images in the text by default. At the same time, images should not be too small, so they do not appear blurry on high-resolution displays.

For many websites, medium image sizes between 600 and 1000 pixels wide make sense. The exact value depends on the theme, layout and intended use.

4. Large image size and hero images

The large image size is often used for wide displays, for example for larger content images, featured images or visual sections. Here you should choose a value that is large enough for your layout, but does not generate unnecessarily many pixels.

For many normal websites, 1200 to 1600 pixels wide are sufficient. For very wide hero sections or high-quality visual projects, larger values may be useful. What matters is how the image is actually displayed.

Avoid using original images directly from a camera or smartphone with a width of 4000 or 6000 pixels without resizing them. Such files are usually oversized for normal website areas.

5. Existing images are not automatically adjusted

When you change the media settings, this normally only affects new uploads. Images that have already been uploaded keep their existing image variants. This is an important point that is often overlooked.

If you want to adapt old images to new sizes, you need a plugin for regenerating thumbnails. Such tools recreate the image variants based on the current settings and theme requirements.

Before taking such action, you should create a backup, especially for large media libraries. Recalculating many images can take time and change storage usage.

6. Organise uploads in month- and year-based folders

WordPress offers the option Organise my uploads into month- and year-based folders. If this option is enabled, WordPress stores uploaded files by year and month, for example:

/wp-content/uploads/2026/05/image-name.webp

This structure is useful for most websites. It prevents all files from ending up in a single large upload folder. This makes backups, file management, troubleshooting and sometimes also work in the cPanel file manager or via FTP easier.

Advantages of this organisation:

• better overview with many files,
• easier file management,
• more practical for large media libraries,
• better traceability of upload periods,
• fewer overcrowded individual folders.

For most WordPress websites, we recommend leaving this option enabled.

7. Control storage space used by images

Images and other media files often consume the most storage space on a hosting account. Especially for blogs, shops, portfolios, galleries or websites with many PDF files, the media library grows quickly.

Storage space is not only used by original images. Automatically generated image sizes, theme thumbnails, WebP versions, backups and optimisation files can also consume storage space.

Check regularly:

• How large is the uploads folder?
• Are there very large original images?
• Do the theme or plugins generate many additional image sizes?
• Are there old media files that are no longer used?
• Are backups stored in the hosting storage?
• Were image optimisations generated multiple times?

• Guide: Monitor storage usage and free up space

8. Optimise file names before uploading

The file name of an image should be chosen sensibly before uploading. WordPress adopts the file name into the media library and also partly uses it in URLs. A descriptive file name is better than a generic camera name.

Poor file names:

• IMG_4938.jpg
• DSC00091.png
• image-final-new-new-2.jpg
• Screenshot 2026-05-15 at 14.31.22.png

Better file names:

• wordpress-media-settings-image-sizes.webp
• curiaweb-hosting-switzerland-dashboard.jpg
• wordpress-contact-form-example.png
• woocommerce-product-image-webp.webp

Use lowercase letters, hyphens instead of spaces and avoid special characters wherever possible. The file name should describe what the image shows. Do not overdo it with keywords.

9. Maintain alt texts in the media library

Besides the file name, the alternative text is particularly important. The alt text describes the content or purpose of an image. It helps screen readers, search engines and users if an image does not load.

A good alt text is short, precise and context-related. It should not be overloaded with keywords.

Poor example:

Hosting Switzerland WordPress hosting fast cheap Curiaweb server SEO image

Better example:

Screenshot of the WordPress media settings with image sizes for thumbnails.

Purely decorative images can have an empty alt text. Informative images, however, should be described meaningfully.

10. Use WebP and modern image formats

Modern image formats such as WebP can significantly reduce file size without greatly affecting visible quality. WordPress supports WebP natively in modern versions, provided the server environment supports the format.

WebP is especially suitable for:

• photos,
• header images,
• featured images,
• product images,
• galleries,
• visual landing pages.

Nevertheless, the following still applies: WebP images should also be correctly scaled and compressed. An oversized WebP image can still be unnecessarily heavy.

11. Use image optimisation plugins sensibly

Image optimisation plugins can automatically compress images during upload, generate WebP versions or optimise existing images afterwards. This is particularly practical for websites with many images.

Typical functions of such plugins:

• automatic compression during upload,
• subsequent optimisation of existing images,
• WebP generation,
• optimisation of different WordPress image sizes,
• backup of original images,
• reports on saved file size.

Before using one, check whether optimisation is performed locally or via external servers. With external services, data protection and contractual issues may be relevant.

12. Media settings and page builders

Page builders such as Elementor, Divi or other builders can use their own image sizes, background images and layout rules. As a result, the normal media settings do not always apply exactly as expected.

Particularly important:

• do not use original images for small tiles,
• compress background images appropriately,
• check mobile image crops,
• use sliders sparingly,
• avoid unnecessary image sizes,
• check image display after changing theme or builder.

If a page builder outputs an image in its full original size, this can significantly worsen loading time. Therefore, deliberately select the appropriate image size if the builder offers this option.

13. Delete unused media carefully

Over time, many files accumulate in the media library. Some of them may no longer be used. Nevertheless, you should not delete media blindly.

An image can be embedded in different places:

• in posts,
• on pages,
• in page builder layouts,
• as a background image,
• in widgets,
• in theme options,
• in products,
• in email templates,
• in CSS or custom code.

WordPress does not always reliably detect whether a file is truly unused. Create a backup before larger media cleanups.

14. Media library and backups

A large media library also affects your backups. The more images, videos, PDFs and automatically generated image sizes exist, the larger backups become and the longer backup and restore processes take.

For efficient backups, it is therefore useful to:

• avoid uploading unnecessarily large original images,
• remove old and clearly unused files,
• limit image sizes sensibly,
• avoid uploading external videos unnecessarily as files,
• test backups regularly,
• keep an eye on storage space in your hosting account.

15. SEO and images in WordPress

The media settings are a technical SEO component. They do not ensure good rankings on their own, but they support fast loading times, clean image delivery and a better user experience.

Especially important for image SEO:

• descriptive file names,
• meaningful alt texts,
• appropriate image sizes,
• compressed files,
• modern formats such as WebP,
• thematically appropriate placement in the content,
• no overloaded image archives,
• mobile optimisation.

Search engines always evaluate images in the context of the page. A good file name helps, but it does not replace high-quality content or a clear page structure.

16. GEO: Make media understandable and machine-readable

GEO, meaning Generative Engine Optimization, also applies to media content. AI-supported search systems benefit from images that are sensibly named, described and embedded in the appropriate context.

Helpful for GEO are:

• descriptive file names,
• precise alt texts,
• captions for explanatory images,
• appropriate headings around the image,
• no important information only as image text,
• structured guides with clear screenshots.

Especially in knowledge base articles, tutorials and technical guides, well-maintained media can significantly improve comprehensibility.

17. Common mistakes with media settings

• Uploading original images directly: Camera or smartphone images are often much too large.
• Wrong image sizes: Theme and media settings do not match.
• Uploads not organised: All files end up in one confusing folder.
• No alt texts: Important images remain poorly described for accessibility and search.
• Keyword stuffing: File names and alt texts are unnaturally overloaded.
• Too many image sizes: Theme and plugins generate unnecessary variants.
• Unchecked deletion: Images disappear from pages, layouts or products.
• No storage control: Uploads and backups fill up the hosting package.

Recommended basic settings and procedure

1. Open media settings: Go to Settings > Media.
2. Check the theme: Check which image sizes your theme actually uses.
3. Set thumbnails appropriately: Choose sensible values for overviews and galleries.
4. Adjust medium and large sizes: Use your website layout as a guide.
5. Leave month and year folders enabled: For better file organisation.
6. Prepare images before uploading: Optimise dimensions, file name and format.
7. Maintain alt texts: Clearly describe important images.
8. Use WebP and compression: Reduce file size.
9. Monitor storage space: Keep an eye on uploads, backups and image variants.
10. Create a backup before bulk changes: Especially when regenerating thumbnails or cleaning up media.

Frequently asked questions about WordPress media settings

Where can I find the media settings in WordPress?

You can find them in the WordPress dashboard under Settings > Media.

Why does WordPress create several image sizes?

So that a suitable image variant can be loaded depending on where it is used. This means a small thumbnail does not have to be delivered as a large original file.

Do new media settings also apply to old images?

Normally not automatically. Images that have already been uploaded keep their existing variants. To recalculate them, you need a plugin for regenerating thumbnails.

Should I organise uploads by month and year?

For most websites, yes. The structure makes file management, backups and overview easier for large media libraries.

How large should images be before uploading?

That depends on where they are used. For normal content images, 800 to 1200 pixels wide are often sufficient; for wide headers or hero images, around 1600 to 2000 pixels. Avoid unnecessarily large original images.

Are file names important for SEO?

Yes, descriptive file names can help. However, they should remain natural and not consist of keyword lists.

Can I simply delete unused media?

Only with caution. Images can be used in page builders, theme options, widgets or products. Create a backup before larger deletion actions.

Does WebP save storage space?

Often yes. WebP can enable smaller files with comparable quality. Nevertheless, images should still be correctly scaled and compressed.