Oct 14, 2025

Mobile Mode: Simpler Interfaces for AI Agents

Run sessions with mobile UA and viewport for simpler DOMs, faster vision agents, and mobile-only auth paths. Keep separate profiles for clean context.

Hussien Hussien

Co-Founder/CEO

Today we're releasing mobile mode for Steel sessions. Pass deviceConfig: { device: "mobile" } when creating a session and the browser appears as a mobile device—user agent, viewport, touch capabilities, and browser characteristics all aligned to look like a phone instead of desktop.

Most websites serve fundamentally different experiences to mobile devices. Desktop sites have nested navigation, hover menus, and complex interactions. Mobile sites strip these away into linear flows and touch-optimized interfaces. For AI agents, this simplification can directly improve task completion.

How it works

import Steel from 'steel-sdk';
import { chromium } from 'playwright';

const client = new Steel({ steelAPIKey: process.env.STEEL_API_KEY });

const session = await client.sessions.create({
  deviceConfig: { device: "mobile" }
});

const browser = await chromium.connectOverCDP(
  `wss://connect.steel.dev?apiKey=${process.env.STEEL_API_KEY}&sessionId=${session.id}`
);

const page = await browser.contexts()[0].pages()[0];
await page.goto('https://example.com');

The session automatically configures mobile viewport dimensions, touch events, and a full mobile device fingerprint. Sites see a consistent mobile device visiting from a browser app, not a desktop browser with a spoofed user agent. Before this, you could override the user agent string, but the rest of the fingerprint wouldn't match - sites would detect the inconsistency.

Mobile mode works with all existing features - proxies, CAPTCHA solving, and session persistence.

Why this matters

Mobile sites present content sequentially rather than using nested menus or hover states. An e-commerce checkout that requires navigating dropdown menus on desktop becomes a vertical list on mobile. Fewer interactive elements means clearer action spaces and less chance of mistakes.

Mobile sites also load faster: fewer widgets, less aggressive lazy-loading—and have simpler DOM structures. Less HTML for your model to process means lower token costs. If you're using vision, it means fewer image token cost too.

Without mobile mode, your sessions use desktop fingerprints by default.