Lumen

Lumen for Windows 10 and 11

A browser made of glass.

Tabs, address bar and bookmarks sit on glass that bends and blurs the page behind them. Underneath is Chromium, so sites work as they do in Chrome or Edge. Free and open source.

Download for Windows Source on GitHub Check your download

Latest release on GitHub · MIT licence

The top of a Lumen window: tab strip, address bar and bookmarks bar drawn as glass over a pale teal and amber page background.
The toolbar over Lumen's new tab page, with Glass on.

What it does.

A daily browser with the glass look on top. These are the things in the current release.

Glass toolbar
Three looks in Settings: Glass, Frosted (blur only, easier on older graphics cards) and Off. Lumen switches to Frosted by itself if drawing gets slow.
Pages are never hidden
Pages start below the toolbar, so fixed headers on sites like YouTube and Gmail stay visible. The glass samples the top of the page and mirrors its colours. A setting lets pages scroll under the toolbar instead (experimental).
Tabs
Drag to reorder, right-click to pin. Background tabs go to sleep after 20 minutes to free memory, and you can change that. Private windows are always dark violet.
Bookmarks
A bar under the address bar, with a menu for the ones that do not fit. Import bookmarks from Chrome, Edge or Brave, or from an exported file. Bookmarks only, no history or passwords.
Ad and tracker blocking
Blocks about 100 well-known third-party ad and tracking networks. It cannot block ads a site serves itself, such as YouTube video ads.
Secure by default
Addresses typed as http:// open over https first, and drop to http only when the site has no https, with a message. Certificate errors stop at a warning page. Camera, microphone and location ask first. Pages run sandboxed.
Updates itself
The installed version checks GitHub Releases at startup and installs a new version when you close Lumen.

Not there yet

Browser extensions (Chrome Web Store extensions do not work in Lumen), a password manager, sync, importing history and passwords, and protected video such as Netflix.

In use.

Screenshots from the current release, taken on Windows 11.

YouTube search results for ABBA in Lumen. The glass toolbar sits above the page, which starts below it.
A normal website. The page starts below the toolbar, so YouTube's own header stays visible. Above busy pages, the glass can look streaky.
Lumen's Settings panel with sliders for blur, refraction, saturation and tint.
Settings. Blur, refraction, saturation and tint can be changed, or Glass switched to Frosted or Off.
Lumen in dark mode: the toolbar and bookmarks bar over a dark new tab page.
Dark mode follows Windows.

How the glass is made.

It is an approximation of the Liquid Glass look, drawn with a shader. It is not Apple's code.

  1. CaptureLumen grabs the top strip of the page about 15 times a second, and less often when nothing on the page changes.
  2. ShrinkThe frame is halved in size and sent to the toolbar layer, a transparent view that sits on top of the page.
  3. DrawA WebGL2 shader paints each glass shape: refraction at the edges, a slight colour split at the rim, blur that is soft in the middle and sharp at the edge, more saturation, and a tint that follows how bright the page is.
  4. Fall backIf the graphics process crashes, Lumen turns Glass off for that session and says so. Your saved setting stays, so Glass comes back on the next start.
drag me

Try it: drag the lens. This is a web version of the effect. In Lumen the same look is drawn by a WebGL shader over the page you are actually viewing.

Changes.

Release notes, taken from GitHub.

  1. Release notes

    See the Releases page on GitHub.

Known issues.

What does not work well yet.

  • Streaky glass above busy pages. Over video thumbnails and similar detail, the glass can look striped. Frosted in Settings is calmer.
  • Some graphics drivers. If the screen flickers or goes black, switch Glass to Frosted or Off in Settings and update your graphics driver.
  • No extensions. Chrome Web Store extensions do not work.
  • Unsigned installer. Windows SmartScreen may warn you the first time.

Found something else? Report it on GitHub.

Check your download.

Lumen is new and its installer is not code-signed yet, so Windows may show a SmartScreen warning. Click More info, then Run anyway.

Some antivirus and sandbox services flag new unsigned installers by mistake. Lumen's releases are built by GitHub Actions from the public source. Newer releases list SHA-256 checksums in a SHA256SUMS.txt file and carry a signed build attestation. Look for them in the release's file list.

Compare the file's hash with the line in SHA256SUMS.txt (PowerShell):

Get-FileHash .\Lumen-0.2.1-x64.exe -Algorithm SHA256

Or verify the build attestation (needs the GitHub CLI):

gh attestation verify .\Lumen-0.2.1-x64.exe --repo SlayThat/Lumen_Browser

Change the version in the file name to the one you downloaded. Only download Lumen from the Releases page. More in SECURITY.md.

Privacy.

Lumen collects nothing about you.

  • No analytics, no crash reports and no account. Lumen has no server of its own.
  • Settings, history and bookmarks stay on your PC, in your Windows user folder.
  • The installed version asks GitHub once at startup whether a newer release exists.
  • Websites you open see your connection, as in any browser. Searches go to the search engine you pick: DuckDuckGo, Google or Bing.
  • The code is public, so you can check all of this in the source.

Look through it.

Download for Windows Source on GitHub Check your download

Windows 10 or 11 · Installer updates itself · Portable build available on the Releases page