Mobile Mode

Overview

Mobile mode allows Steel sessions to appear as mobile devices. Pass deviceConfig: { device: "mobile" } when creating a session and the browser presents itself with mobile user agent, viewport, touch capabilities, and browser characteristics—everything 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

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import Steel from 'steel-sdk';
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import { chromium } from 'playwright';
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const client = new Steel({ steelAPIKey: process.env.STEEL_API_KEY });
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// Create a session with mobile device configuration
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const session = await client.sessions.create({
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  deviceConfig: { device: "mobile" }
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});
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// Connect to the mobile session
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const browser = await chromium.connectOverCDP(
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  `wss://connect.steel.dev?apiKey=${process.env.STEEL_API_KEY}&sessionId=${session.id}`
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);
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const page = await browser.contexts()[0].pages()[0];
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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 including proxies, CAPTCHA solving, and session persistence.

Why This Matters

Simplified Navigation

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.

Performance and Cost Benefits

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

Consistent Fingerprints

Without mobile mode, your sessions use desktop fingerprints by default. Mobile mode provides a complete, consistent mobile device fingerprint that websites trust.