# Pixelscan stuck on scanning: a non-verdict, not a pass > Pixelscan stuck on scanning for 90 seconds was, in our runs, a profile claiming Windows on a Mac. A scan that never returns is a non-verdict, not a slow pass. Source: https://mosaicbrowser.com/blog/pixelscan-stuck-on-scanning ## When Pixelscan never stops scanning Pixelscan stuck on scanning for 90 seconds was, in our runs, a profile claiming Windows on a Mac. A scan that never returns is a non-verdict, not a slow pass. ![90s: Three Windows claims, three scans that never ended](https://mosaicbrowser.com/covers/pixelscan-stuck-on-scanning.webp) When Pixelscan is stuck on scanning, the page has loaded and its headline still reads "Your Browser Fingerprint is scanning…" with no verdict after it. The one cause we have reproduced is a profile claiming Windows on a Mac: three such profiles never finished. A scan that never returns is a non-verdict, and we report it as one. ## What we saw The report that started this was a screenshot of two red Pixelscan cards over a profile claiming Windows. We could not reproduce the bot card at all. One fresh profile on this Mac's own platform, no proxy, three rounds through our detector runner, came back with five green cards, and an untouched Google Chrome on the same machine and the same address read the same. That control is the reason the row means anything. Then we changed one thing, the platform the profile claims, and ran the same page the same way. Same host, same engine, no proxy on any row: | Claimed platform | Pixelscan headline | | --- | --- | | macOS (this computer), twice | consistent, no masking | | Linux | inconsistent, "Masking detected" | | Windows, three separate profiles | "scanning…" still showing at 90 seconds | The Windows rows were not slow pages. Each one was complete and visible, with 11,538 characters of it rendered, and the headline simply never moved past "scanning…". We stopped waiting at 90 seconds on all three. ## Why a scan that never ends is worse than a fail A fail tells you what the site concluded. A scan that hangs tells you the site could not reach a conclusion about this browser, which is information too, and none of it is good. A real Windows laptop gets a verdict from Pixelscan. A browser that leaves a detector unable to finish is less usable on that site than one that fails it outright. So in our detection reports a hang is recorded as "no verdict", next to pass and fail and never folded into either. A runner that waits a fixed time and then marks anything without a red word as a pass would have called all three Windows profiles clean. Mosaic is a desktop app Email yourself the link and open it on your computer. [How it works: Machines that exist](https://mosaicbrowser.com/features/real-fingerprints) ## The Linux row prints the cause The two profiles that did finish show why the third kind could not. Pixelscan's "What Websites See About You" table lists the fonts it found: - claiming macOS: font hash `24d9fa4d…`, Al Bayan, Al Nile, Al Tarikh and 152 more - claiming Linux: font hash `31aca820…`, Abyssinica SIL That is 159 fonts against one. Pixelscan probes the font list that belongs to the platform the browser claims, and the fonts actually installed belong to the computer it runs on. No switch in our engine reaches them, because the files, their metrics and the way the system rasterises them come from the real machine. The longer story of how fonts decide this verdict is in [Pixelscan's masking verdict, bisected to one surface](https://mosaicbrowser.com/blog/pixelscan-masking-bisected), and the platform rule is in [a Mac makes Mac profiles](https://mosaicbrowser.com/blog/a-mac-makes-mac-profiles). We can say what Pixelscan reads, because its collector script declares it. We can't say why the Windows case hangs instead of failing, because the verdict is computed on Pixelscan's server. ## Our own harness got it wrong twice first Two faults in our reader would each have given a confident wrong answer, and both are worth checking in any script you point at this page. The first matched the site's menu. Reading the word after "Fingerprint" out of the page text finds Pixelscan's navigation, "Fingerprint Check" and "Checkers", long before it finds the card. Six clean profiles were scored as six failures with the card apparently reading "Checkers". The reader now cuts the page down to the scan section before it looks. The second was timing. The headline paints in two steps: it shows "Your Browser Fingerprint is " with the verdict word not yet drawn, then the word. A poller that waits only for "scanning" to disappear catches that in-between frame, and one run in twenty scored a fail with all five cards clean underneath it. We now wait for the verdict word itself, and if it never comes, the run is a hang. ## When Pixelscan is stuck on scanning, check these first Check the profile against the machine first. A profile claiming Windows or Linux on a Mac is the case we measured, and in Mosaic the profile editor says when a claimed desktop OS is not the one this computer runs. The values the engine draws to match the machine are listed on [real fingerprints](https://mosaicbrowser.com/features/real-fingerprints). Then run the control. Open Pixelscan in an untouched Google Chrome on the same computer and the same connection. If stock Chrome hangs too, the problem is the site or the network, not the profile, and no setting will fix it. Read the verdict word, not the absence of a red one, and run it more than once, because Pixelscan disagrees with itself between runs. How the fingerprint, the proxy and the cookies fit together for accounts you are entitled to run is in [how to manage multiple accounts without getting linked](https://mosaicbrowser.com/guides/how-to-manage-multiple-accounts-without-getting-linked). ## Questions ### Why is Pixelscan stuck on scanning? The one cause we have reproduced is a profile claiming Windows on a Mac. Three profiles claiming Windows on a Mac each left the headline reading scanning past 90 seconds, with the page fully rendered. ### Does a long Pixelscan scan mean the browser passed? No. A headline that never names a verdict is a non-verdict. We record it as no result, never as a pass, and we treat it as worse than a fail because the page could not finish its own check. ### How long should a Pixelscan scan take? We don't have a published figure from Pixelscan. In our runs, profiles that matched the machine came back with a verdict well inside the 90 seconds we waited; the Windows claims never did. ### How do I tell whether the problem is my profile or the site? Open the same page in an untouched Google Chrome on the same computer and the same connection. If stock Chrome also hangs, the hang is not about your profile. ## Related [Pixelscan's masking verdict, bisected to one surface](https://mosaicbrowser.com/blog/pixelscan-masking-bisected): We bisected Pixelscan's masking detected verdict on one profile. Canvas, WebGL, audio and client rects were fine. Hiding about 2% of font families caused it. [Why OS spoofing fails on fonts: a Mac makes Mac profiles](https://mosaicbrowser.com/blog/a-mac-makes-mac-profiles): Why OS spoofing fails on fonts: they come from the computer, not the claim. A Linux profile made on our Mac showed 1 font where macOS showed 159. [Machines that exist: fingerprints drawn from real hardware](https://mosaicbrowser.com/features/real-fingerprints): Mosaic draws each profile's GPU, screen, CPU, memory and fonts from one real device, so the parts of a fingerprint agree with each other and with the host. [How to manage multiple accounts without getting them linked](https://mosaicbrowser.com/guides/how-to-manage-multiple-accounts-without-getting-linked): Accounts get linked by shared cookies, IPs, fingerprints and habits. Give each its own profile, exit and history, then test it before you trust it.     ## Mosaic, on your own computer The browser this blog is about: its own Chromium, fingerprints from real machines and a proxy exit per profile. Free holds 3 profiles. Pro is $49 a month for any number. Mosaic is a desktop app Email yourself the link and open it on your computer.