Structured browser perception

What it is, and why your AI needs it. Definitions, the reliability-compounding argument, and how the approaches compare.

Definition

Structured browser perception gives your AI a machine-readable representation of a live rendered page: element identity, text, layout and state. Your AI reasons over this structure instead of pixels or raw markup.

Why the category exists: reliability compounds

Reliability compounds across a multi-step workflow. Even a strong per-action result can produce a weak end-to-end result when every step depends on the one before it.

Perception that resolves elements structurally rather than visually improves the reliability of each step. The benefit compounds across the complete workflow. This is an argument about architecture, not about any single product.

The three approaches

Source article for this comparison: Runtime Snapshots 16

Three ways to give your AI a page, compared on the dimensions that decide real-world use.

ApproachCost / pageAuthenticated coverageElement addressingDrift
Screenshots + visionHigh (vision tokens)YesNoHigh
Static HTML / DOM extractionLowPartialYes (noisy)Medium
Runtime structural perceptionLowYesYesLow

Where E2LLM sits

E2LLM is one implementation of runtime structural perception. It captures the rendered page as a structured representation after the page has loaded, in the session the user is already using.

Format reference for this implementation: SiFR

Current boundaries

Structured perception depends on information the browser can expose. Canvas applications, image-only content and controls inside closed shadow roots may require visual input or a workflow-specific integration. Browser-internal pages, closed tabs and expired sessions also remain outside the active page state. A reliable agent identifies these boundaries and routes the step to an appropriate visual tool, supported integration or human review.

Choose your next guide

Start with the task that matches what your agent needs next. Each guide connects a practical browser workflow to structured browser perception: current page state, grounded actions and verification in the browser session where the work happens.

Connect an AI to the browser

Automate browser workflows

Compare perception and recover from failures

Further reading