Limits and troubleshooting
Upload size and file limits by plan, plus fixes for the common problems — a blank page, a 404 when refreshing, a rejected file type, and a preview that looks broken.
Purpose
What the limits are, and how to fix an upload that does not work.
Limits
| Light | Standard | Full | |
|---|---|---|---|
| ZIP upload | 25 MB | 50 MB | 200 MB |
| Site size once unpacked | 75 MB | 150 MB | 600 MB |
| Number of files | 1,000 | 3,000 | 10,000 |
| Largest single file | 25 MB | 25 MB | 50 MB |
| Versions kept | 3 | 5 | 10 |
For scale: a typical React conference site is 1–5 MB. If you are near the limit it is almost always video — host that on YouTube or Vimeo and embed it, which is better for your visitors anyway.
The site is blank, or unstyled
Almost always the ZIP structure. Open the ZIP and look at what is at its top
level: you should see index.html there directly. If instead you see a single
folder that contains index.html, you zipped the folder rather than
its contents.
If the browser console shows Uncaught SyntaxError: Unexpected token '<', the
site is asking for a JavaScript file that is not in the upload. Rebuild and
re-zip, making sure the whole assets/ (or static/) folder is included.
The preview looks broken but the upload succeeded
This is expected for some builds, and the upload notes will say so.
The preview shows your site at a temporary address underneath the app, while your
published site gets an address entirely of its own. Sites that reference their
files by absolute path — /assets/app.js, which is what Vite and Create React
App produce by default — cannot resolve those paths at the temporary address, but
resolve them perfectly once published.
If the notes on your upload mention absolute paths, publish it and check the real
address. If you would rather have a preview that works, build with a relative
base (base: './' in vite.config.js, or "homepage": "." in package.json
for Create React App).
A page 404s when I refresh it
Single-page apps (React Router, Vue Router) handle their own URLs. We serve
index.html for addresses that do not match a file, so refreshing a deep link
works — but only for paths without a file extension. If a real asset is missing
you get a genuine 404, which is deliberate: it shows you the broken file instead
of hiding it behind your homepage.
"This file type is not supported"
We serve only standard web files: HTML, CSS, JavaScript, images, fonts, video, PDFs, and similar. The upload names the file that caused the rejection.
Usually it means the project source was zipped instead of the build output.
Rebuild and upload the dist/, build/, or public/ contents.
Server-side files — .php, .jsp, .sh, executables — are refused outright,
because they would never run here and their source would otherwise be readable by
anyone.
"This conference cannot host a website yet"
Your conference's URL slug is also its web address, so it has to be a valid one: lowercase letters, numbers, and hyphens only, no underscores, no leading or trailing hyphen, 63 characters or fewer. Change it in the Setup tab and come back.
The slug appears in every /c/your-slug/... address you have shared. Change it
before you publicise anything, not after.
Nothing here fixed it
Contact support with your conference acronym and the version note of the upload that failed. The exact error is recorded against that version.