Most owners meet the WordPress media system sideways. You want a new photo of the shop on the About page, so you drag it into the editor, and it works. Then a month later the same photo appears in the Media Library four times, the blog thumbnail is cropped through someone’s head, and a staff member asks where the PDF price list “lives”. None of that is mysterious once you see how the pieces fit.
This guide explains how images and media in WordPress actually work: where files go when you upload them, the difference between an image placed in a page and a featured image, the extra copies WordPress makes behind your back, and where alt text fits. Each task has its own short guide, linked as we go.
The Media Library: where images and media in WordPress are kept
Everything you upload, whether from the editor or from Media → Library, ends up in one place. The Library is a shelf of files. It does not decide where anything appears on your site. A photo sitting in the Library is invisible to visitors until a page, a post, a template or a setting asks for it.
Two views are worth knowing. The grid view shows thumbnails and is handy for finding something by eye. The list view (the icon with lines, top left of the screen) shows file names, the date of upload and, usefully, which post or page the file was first “uploaded to”. That last column only records where a file was first attached, not every place it is used, so do not treat it as a usage report.
Click any item and the Attachment details panel opens. Here you can edit the alternative text, title, caption and description, copy the file’s address, and open the built-in image editor. Changes you make here are stored with the file in the Library. Whether they reach a page that already uses the image depends on how it was placed, which comes up again below.
Where the files physically sit
On the server, uploads go into wp-content/uploads/, usually in folders by year and month. That is controlled by the “Organize my uploads into month- and year-based folders” box under Settings → Media, which is ticked on most sites. You rarely need to touch those folders yourself, but it helps to know that the Library is a list in the database pointing at real files in that folder. If someone deletes the files over FTP, the Library still lists them, with broken thumbnails.
How to add images to WordPress: three routes
There are three common ways to add images to WordPress, and they end up in the same Library.
- From inside the editor. Add an Image block and choose Upload, or drag a file from your computer straight onto the page. The file is uploaded to the Library and placed in that block in one step.
- From the Library first. Go to Media → Add Media File (older versions call it Add New), upload a batch, fill in the alt text while you are there, then pick them from the Library when you build the page.
- From another place on the site. Theme settings, logos, site icons and some plugin screens have their own “Select image” buttons. These open the same Library window.
Uploading a batch first is the tidier habit for a business site, because you write descriptions once and avoid uploading the same photo twice. The step-by-step version, including alignment and wrapping text around a photo, is in our guide on adding an image to a WordPress page.
If an upload fails with a size message, that is a server limit rather than a WordPress setting, and our post on the maximum upload size in WordPress explains how to raise it safely.
An image in a page and a featured image are different things
This is the distinction that confuses people most. An image you place with the Image block belongs to that page’s content. It appears exactly where you put it, and only there.
A featured image is a single image attached to a post or page as a setting, chosen in the sidebar of the editor. Your theme decides where it shows: at the top of the post, as a thumbnail on the blog page, in related-post lists, sometimes nowhere at all on pages. SEO plugins also tend to offer it to Facebook, LinkedIn and WhatsApp when someone shares the link. So the same photo can be a featured image and also sit inside the content, and you may see it twice on the post if you do both.
How to choose one, what shape works across most themes and how it relates to sharing previews is covered in setting a featured image in WordPress.
The copies WordPress makes of every image
When you upload one photo, WordPress quietly creates several smaller versions of it. The sizes in Settings → Media are the visible ones: by default Thumbnail (150 by 150, cropped to a square), Medium (up to 300 pixels) and Large (up to 1024 pixels). Core WordPress also makes a few more sizes you will not see listed there, and your theme and plugins often register their own. One upload can easily become a dozen files.
Two more behaviours are worth knowing:
- Very large photos are scaled down. If you upload a straight-from-the-camera image wider or taller than 2560 pixels, WordPress keeps your original but creates a version with
-scaledin its name and uses that as the “full size” version. - Changing the sizes later does not touch old images. New sizes apply to new uploads. Old images need their sizes regenerated with a plugin, which is where the post on blurry or wrongly cropped WordPress images picks up.
None of this shrinks what you upload. Put a 6 MB phone photo in and a 6 MB original sits on the server alongside its smaller copies. Resize and compress before upload, and use the built-in editor only for small corrections, as explained in our guide to cropping and resizing an image in WordPress.
Alt text, captions and the other fields
Each image has four text fields, and they do different jobs. Alternative text is read aloud by screen readers and shown when the image fails to load; it is the one field that genuinely matters on every meaningful image. The caption is visible text under the image. The title and description are mostly internal and rarely shown by themes.
One detail catches people out. When you place an image in a block, WordPress copies the alt text from the Library into that block. If you later fix the alt text in the Library, images already placed in pages keep the old wording. You have to update the block too. Our guide on writing and adding alt text in WordPress covers that, plus decorative images, and the companion post on captions, titles and descriptions explains which of the other fields show where.
Media that is not a photo
The Library holds more than images. PDFs, Word documents, audio files and short videos can all be uploaded, within the file types WordPress allows. Each has a sensible way to go on a page:
| What you have | Usual approach | Guide |
|---|---|---|
| A brochure, menu or price list | Upload the PDF and use the File block | Adding a PDF to a WordPress page |
| A video | Host it on YouTube and embed it, rather than uploading it | Embedding a YouTube video |
| Several photos of one job | The Gallery block | Covered in the gallery guide in this section |
| A large banner with text on it | The Cover block | Covered in the Cover block guide in this section |
On video specifically: you can upload an MP4 and use the Video block, but large files eat hosting storage and bandwidth, and they play less smoothly than a service built for streaming. For a business site, a streaming service with an embed on the page is usually the calmer arrangement.
Changing and replacing what is already there
Swapping a photo on one page is easy: select the Image block and use Replace. Swapping a file everywhere it appears, or updating a PDF that people already link to, is a different job, because WordPress gives every new upload its own new address. Our guide to replacing an image in WordPress explains both, and when a replace plugin is worth installing.
Deleting is the risky direction. Deleting a file from the Library removes it from every page that uses it, with no warning about where it was used. Before any tidy-up, read our post on cleaning up the Media Library safely.
Images and page speed
Heavy images are one of the most common reasons a small business site feels slow, particularly on phones. That is its own subject, with its own section on our site: start with the guide to image optimization for a website if your pages are sluggish. The short version for daily work is to resize before you upload and to avoid placing a full-size original where a smaller version would do.
This section sits within our WordPress management guide, which covers the rest of looking after a site: settings, the editor, menus, plugins, forms, SEO and users.
Frequently asked questions
Can I organise the WordPress Media Library into folders?
Not with WordPress alone. The Library can be filtered by type and by month, and searched by file name or title, but it has no folders of its own. Media folder plugins add a folder view for the admin screen without moving the real files. For most small sites, clear file names and good titles make search enough.
Why does the same image appear several times in my Media Library?
Usually because it was uploaded more than once, often by dragging it into different pages. WordPress does not check for duplicates, so each upload becomes a separate item with its own address. The extra sizes WordPress creates do not show as separate items, so repeated entries are genuinely repeated uploads.
What image formats can I upload to WordPress?
JPEG, PNG, GIF and WebP are accepted by default, and recent versions also accept AVIF if your server supports it. SVG files are blocked by default because they can contain code; adding them needs a plugin that cleans the file. For photos, JPEG or WebP is the usual choice, and PNG suits screenshots and graphics with flat colour.
Can other people on my site delete images I uploaded?
It depends on their role. By default, Authors and anyone above them can upload files and browse the whole Library, but an Author can only edit or delete their own uploads. Editors and Administrators can change or delete any file, and Contributors cannot upload at all. If several staff add content, give Editor accounts only to the people who need them.
Media problems build up quietly over the years: broken images after a move, the same photo uploaded five times, a price list nobody can find. If you would rather hand that tidy-up to someone else, it is the sort of job our WordPress support service takes on for small business sites.
All guides in this section
- How to Add an Image to a WordPress Page
- How to Add Alt Text in WordPress, and What to Write
- How to Crop an Image in WordPress and Resize It
- How to Set a Featured Image in WordPress
- How to Add a PDF to WordPress: Embed or Download
- How to Embed a YouTube Video in WordPress
- How to Replace an Image in WordPress (Same URL or New)
- WordPress Cover Block: Build a Readable Hero Image
- How to Add a Gallery in WordPress With the Gallery Block
- Media and Text Block in WordPress: Image Next to Text
- WordPress Image Caption, Title, Alt and Description
- Free Images for a Business Website: Licences Explained
- Image Lightbox in WordPress: Click to Enlarge Images
- How to Download the WordPress Media Library
Next in this series: How to Add an Image to a WordPress Page
