AI Overlay that Lives on your Desktop

Lumen sits directly on top of your work. Press Ctrl+Space over any app to explain, solve, or summarize what you see — without switching context.

Download for Mac

Free to start · No credit card required · Windows 10/11 & macOS

Choose what you need help with. Lumen captures the exact pixels on your screen and outputs actionable answers without switching windows.

Code & ErrorsFormulas & MathDense ReadingFull Display

Read the error, hand back what fixes it.

Highlight a stack trace, syntax error, or broken function. Lumen identifies the root cause and outputs the corrected code block ready to copy and paste.

Lumen's Direct SolutionCopy solution

Root cause: unhandled null response payload

// Replace line 42:

const items = response?.data?.items ?? [];

Guards against null/undefined API payload with safe nullish coalescing default.

Ready to pasteDrop into your editor

Open. Select. Solved.

Three quick actions between hitting a blocker and getting back to work.

Press Ctrl+Space (or Cmd+Space on macOS). The translucent overlay floats over your current workspace in milliseconds.

Drag a bounding box around any problem on screen—code, math, diagrams, or text. Or let Lumen analyze the entire active display automatically.

Lumen answers directly over your screen. Get the exact corrected code block ready to paste, step-by-step logic, or summaries, and keep moving.

Recording a tutorial, presenting to clients, or on a live video call? Lumen tells your operating system to hide its screen from capture, so your answers and overlay never leak into recordings.

Excluded from Zoom · Microsoft Teams · Google Meet · OBS Studio · Loom · Slack Huddles

Drag the handle to test real-time visibilityHidden from taskbar & Alt+Tab

Native window exclusion

Uses Windows WDA_EXCLUDEFROMCAPTURE to block GPU frame grabbers at the driver level.

Lumen does not create taskbar buttons or Alt+Tab thumbnails while running. It appears and disappears seamlessly.

Screen content is only read when you press the hotkey and select an area. It never records in the background.

Start with free everyday screen selection and problem solving. Upgrade to Pro for 20x capacity and Stealth Mode.

For everyday debugging, formula resolution, and text explanation.

5 requests per day

Instant overlay with Ctrl+Space

Screen region selection & full display analysis

Code debugging & math problem solving

Local session history saved on device

Download Free

RECOMMENDED

Pro

Power users

20x request capacity, GPT-6 Luna reasoning, and Stealth Mode privacy.

100 requests per day (20x capacity)

GPT-6 Luna — ~4.3x more capable than Free

Stealth Mode: 100% invisible on Zoom, Teams & OBS

Priority low-latency processing queue

Direct priority developer support

Get Pro — $20/month

Detailed plan comparison

Compare all features, models, and privacy protections across tiers.

IncludedIncludedScreen Region SelectionIncludedIncludedFull Display AnalysisIncludedIncludedLocal Device HistoryIncludedIncludedStealth Mode (Screen-Share Privacy)Excluded from Zoom, Teams, Meet, and OBS via OS capture exclusion API—Not includedIncludedPlatforms & SupportSupported SystemsWindows 10/11 & macOSWindows 10/11 & macOSSupport LevelStandard supportDirect priority developer support

Frequently asked questions

Everything you need to know about privacy, hotkeys, and platform support.

Lumen uses lightweight native OS APIs to capture the exact pixels only when you invoke Ctrl+Space (or Cmd+Space on macOS) and make an explicit selection. It never records your screen continuously in the background or monitors keystrokes.

On Windows, Lumen applies the native WDA_EXCLUDEFROMCAPTURE window display affinity flag. This tells the Windows Desktop Window Manager (DWM) compositor to omit the overlay window from any GPU capture stream used by Zoom, Microsoft Teams, Google Meet, OBS Studio, and Discord.

Your desktop conversations and prompt history are stored locally on your device in your user directory. They are never synchronized to public databases or shared between users.

Screenshots are only processed ephemerally for the immediate request you submit. They are discarded immediately after generating the response and are never used to train frontier foundation models.

Pro is $20 per month on a monthly plan, or $15 per month when billed annually as $180 per year. Checkout runs directly through Stripe. You can upgrade, manage invoices, or cancel anytime from the Billing dashboard.

Install Lumen for Windows or macOS. Press Ctrl+Space whenever you need help with what you see on screen.