bolt.new preview
This is the address in your editor tab. Nobody else can open it, because it was never actually a server to begin with. That is different from your app being down or broken.
What you see
It's running, just for you
Your app is running entirely inside this browser tab, on your machine. There is no server anywhere. That address can even change the next time you open the project.
Serving in this tab
What anyone else sees
There's nothing for them to open
If you send that same link to a client, a friend, or a checking tool like PeerRun, they land on an empty error page. Not because your app is broken, but because there is genuinely nothing there for them to reach.
404 empty page
For Bolt.new
Bolt runs your app in your browser tab. There is nothing for anyone else to open.
If you paste your bolt.new preview link into a checking tool, including us, the honest answer is we cannot reach it. We will not fake a green checkmark. Download your project or push it to GitHub instead, and we can check that.
Last verified 18 August 2026. We tried it ourselves. This is not a guess.
Why this is not a glitch
Your Bolt preview is not hosted anywhere. It only runs in your tab.
Bolt's editor preview (built on technology called StackBlitz WebContainers) runs your whole app, including the parts that would normally live on a server, inside your browser using tricks that make the browser act like a mini computer. Nothing is actually hosted anywhere. Every project even gets its own web address, but that address can change the next time you open it.
The technical detailWebContainers are a browser-based runtime for executing Node.js applications and OS commands, entirely client-side, via Service Worker and WebAssembly across several domains.
That is why pasting a link into a checking tool is the wrong approach for Bolt. There is nothing waiting on the other end for anyone else to load. This is true for every outside tool, not only PeerRun.
Cited: WebContainers introduction, browser config. TARGET_ACCESS §3.1.
Two different kinds of Bolt link
Your editor preview and your published site are not the same thing.
*.bolt.host (and optional Netlify)
When you publish your project, it gets a real, working address that anyone can open, free on a .bolt.host domain. You can add Netlify too, but by Bolt's own admission, Netlify alone cannot host your database or anything that needs a real backend.
Cited: Bolt hosting, Netlify. TARGET_ACCESS §3.3.
The only honest path
Export the ZIP, or push to GitHub.
Download ZIP
In Bolt, use Export, then Download ZIP. Unzip it, install it, and run it on your own computer. Then sign in to PeerRun and add that folder. For Bolt, this is the only way to get an app that was never published in front of an outside check.
GitHub (and Supabase, if you connected it)
If you connected GitHub, and Supabase for your database, those come along when you push your code. The part you can see can be complete, but your database lives in a separate place. If you do not also give us access to that, we report BLOCKED or UNKNOWN, and say why.
Cited: projects and files. TARGET_ACCESS §5.7 (U14 resolved against official docs).
What Bolt already checks
Scanning your code for security holes is not the same as using the app.
Bolt offers a security audit that reviews your code and database for problems. That is real and useful, but it is a different job from actually clicking through your app to see if sign-in, checkout, or anything else works. We are not saying Bolt apps are especially buggy. We are saying the in-tab preview cannot be reached from outside, and a code scan is not the same as someone using the app.
Cited: Bolt security. TARGET_ACCESS §3B.2.
- Signed-in product
- Even once you have published to .bolt.host, anything behind your login screen stays Unknown until you give us access.
- A bot wall
- If a robot-check stops us, that is Blocked, not broken. We will not try to get around it.
- The preview link
- We cannot see inside your editor tab, and we will say so plainly. We will not call that error page proof your app failed.
- What we do not claim
- We do not have a special Bolt integration. Your published *.bolt.host site is not unreachable, that part works fine. And we have not measured how often Bolt apps fail overall.
Questions people actually ask
Bolt, specifically
I pasted my preview link and everything said 404. Is the app broken?
Not based on that alone. That preview link was never a real server to begin with. Export your project, or open your published .bolt.host link if you have one.
Can PeerRun see my app if I just leave the tab open?
No. What is running in your tab is not connected to the public internet, no matter how long you leave it open. We will not pretend otherwise.
I published to .bolt.host. Now what?
That link works, and anyone can open it. But it only proves the parts anyone can see without logging in. Bring us the repo or folder too, and grant access, if you want the signed-in parts checked.
Sources
What this page is allowed to say
- WebContainers introduction and browser config
- Bolt project files, hosting, security
- In-repo: docs/research/PEERRUN_TARGET_ACCESS_STRATEGY.md §3.1, §3.3, §5.7
If the only link you have is the preview, there is nothing to check yet.
Sign in and bring your exported folder or your GitHub repo.
We will not invent a pass. Anything behind your sign-in stays Unknown until you grant access. A robot-check is Blocked, not broken. The first look is on us.