When an image you send on Discord shows up as a downloadable attachment instead of an inline preview, Discord's documentation points at two verifiable causes, both listed under File Upload Settings → Desktop/Browser in the File Attachments FAQ: the setting covering directly uploaded images, and a size rule — "Any image that is larger than 20MB will be shared as a download instead."
There is a lot of advice about caches, browser extensions and slow connections. None of that appears in Discord's File Attachments FAQ, so none of it appears here.
Preview versus attachment: what Discord documents
Discord's File Attachments FAQ describes its file upload settings under a heading that names the scope out loud: File Upload Settings → Desktop/Browser. Three entries in that list decide whether an image is displayed or shared as a download, and they are worth reading in Discord's own words:
- "When posted as links to chat: When an image is posted as a link, the image will be displayed instead of the text link."
- "When uploaded directly to Discord: Any image that is larger than 20MB will be shared as a download instead."
- "Show embeds and preview website links pasted into the chat: Embeds and website links will display a preview, unless disabled."
Two of these matter for this bug. The first governs images that arrive as links — you paste a URL pointing at an image, and Discord renders the picture rather than the raw text. The second governs images you upload directly. Those are separate entries, which is why one can behave differently from the other.
The third covers website link previews in general: embeds and website links preview "unless disabled", so if pasted links stopped showing anything at all — not just images — start there. For where these settings live in the client you are using, check the official documentation.
Cause 1: the file upload setting
If images you upload directly arrive as file cards regardless of which image you send, that is not a per-image problem and no amount of re-exporting will fix it. The FAQ's "When uploaded directly to Discord" entry covers that path, listed in the Desktop/Browser section of Discord's file upload settings.
What makes this diagnosis easy is that a settings problem does not pick and choose between images: every direct upload behaves the same way. If the behaviour is inconsistent — this image previews, that one does not — the setting is not your problem, and the size rule below almost certainly is.
Cause 2: the image is larger than 20MB
The second documented cause sits in the same Desktop/Browser list, stated flatly: "Any image that is larger than 20MB will be shared as a download instead."
This is a display rule, separate from the upload cap, which decides whether a file can be sent at all. The FAQ states that cap on its own terms: "For non-Nitro subscribers, the maximum file upload is 20MB." It adds "Nitro Basic offers 50MB and Nitro offers up to 500MB." Discord's Server Boosting FAQ adds "50MB Upload Limit for all members (server only)" at Level 2 and "100MB Upload Limit for all members (server only)" at Level 3. The "(server only)" is Discord's own parenthesis: those numbers apply inside that server.
Where more than one applies, the developer reference gives the official arithmetic: the limit "applies to each file in a request", and the attachment_size_limit value "provided when working with interactions is calculated as the maximum of these values." Maximum, not sum — and per file, not per message.
The fix for the display rule is the simple one: get the file under 20MB.
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
If you would rather set the knobs yourself, the video compressor exposes the same machinery.
One caveat before trusting any number here: Discord states at the top of that FAQ that it is "currently experimenting with various file upload size limits" and that "Select users may have the ability to upload larger file sizes." Verify against the official page before building a workflow around it.
Not every file is supposed to preview
If the thing you sent is not an image, there is nothing to fix. Discord documents this as normal behaviour: "If you attach non-image files, such as a PDF, DOC, etc. the files will display as embeds in your message and will not provide a preview of the attached file."
A PDF page or a slide looks like an image, but neither is one as far as Discord's renderer is concerned. Export it as a PNG or JPEG if you want it inline.
Video is its own case: Discord's documentation does not state a size at which a clip stops playing inline and becomes a download link, so any threshold quoted for that is not from Discord's help pages. If a clip is the actual problem, Discord says your file is too large covers how the upload cap is measured.
A third case that looks similar but is not
Sometimes the image never arrives at all, which reads as "it sent as a file" until you look closely. Discord documents one non-size reason: "To help keep users safe, we have both User Settings and Server Settings to scan images for NSFW content. If these settings are enabled and the system detects the image could be NSFW, it will block the upload."
Keep the condition attached — this applies if those settings are enabled, at the user or server level. A blocked upload and a download card are different outcomes, and telling them apart takes one glance: did the message post with an attachment on it, or not at all?
Multiple images in one message
If you send several images at once and the layout surprises you, that is documented too: "If you upload multiple video files, images, or GIFs in one message, they will be sent together and displayed as a mosaic format." That is a documented layout, not a failure, and it covers video files and GIFs as well as images. The FAQ says nothing further about the mosaic, so treat anything more specific as unverified.
When a preview worked and then stopped
If the image is shown through a Discord CDN link somewhere outside Discord — a forum post, a wiki, someone else's site — and it eventually goes dead, the developer reference documents why: "Attachments uploaded to Discord's CDN (like user and bot-uploaded images) have signed URLs with a preset expiry time." Inside the client this is invisible, because "Discord automatically refreshes attachment CDN URLs that appear within the client".
Discord does not publish how long that preset expiry is, so treat any specific number you find as unverified. The reference does note that "The standard CDN endpoints listed above are not signed, so they will not expire" — the split is between signed attachment URLs and the standard endpoints.
How to tell it worked
Check in this order:
- Send a small JPEG or PNG, well under 20MB. If that previews, your settings are fine and size was the issue.
- Confirm the file is actually an image. A PDF or DOC shows without a preview no matter what you do to it.
- Check that the message posted at all. A blocked upload is a different outcome from a download card, and the NSFW scanning setting above is the documented cause of the first one.
FAQ
Why is Discord sending my images as files instead of previews? Discord's File Attachments FAQ documents two causes, both under its File Upload Settings → Desktop/Browser section: the setting covering images uploaded directly to Discord, and the rule that "Any image that is larger than 20MB will be shared as a download instead." Anything outside those two is not stated in Discord's help pages.
Does Discord have a size limit for image previews? Discord's Desktop/Browser file upload settings state that "Any image that is larger than 20MB will be shared as a download instead." That is a separate rule from the upload limit: the upload limit decides whether the file can be sent at all, and the display rule decides whether an image that was sent gets rendered inline. See our Discord upload limit breakdown for how the cap itself is measured.
Why do PDFs never show a preview on Discord? Because that is the documented behaviour for non-image files: they "display as embeds in your message and will not provide a preview of the attached file." Convert the page to PNG or JPEG if you need it visible inline.
Is the 20MB display rule the same on mobile? Discord places that sentence under File Upload Settings → Desktop/Browser and does not restate it for other clients, so check the official documentation for the client you are on.
Does compressing the image hurt quality enough to matter? For anything viewed in a chat window, rarely. A screenshot or photo that lands well over 20MB is usually carrying resolution nobody in the conversation will ever see. The same reasoning applies to clips — see how to compress a video without losing quality.
Chasing the same symptom elsewhere? Slack image previews not showing covers it with a different rule set, and the rest of the fix guides and browser-based tools are worth a look.
Quotations above are from Discord's File Attachments FAQ, Server Boosting FAQ, and developer API reference, checked 16 September 2026. Discord has changed these numbers before — verify against the official pages before relying on them.
