v147 · proposed IWA API · member reference
WebPrintingManager.getPrinters()
Lists printers locally available to the operating system after the browser grants access. The stable path preserves the old “navigator printing” label, but the actual receiver is window.printing.
Syntax
window.printing.getPrinters()
// Promise<WebPrinter[]>Inputs
No parameters. It gathers all OS-local printers; there is no standardized filter, chooser parameter, or signal.
Outputs
Resolves to a sequence of WebPrinter objects. Each cache initially has printerName and printerId; the normative algorithm says the ID must be an obfuscated SHA-256 hex representation. An empty list is possible if no printers are available.
Errors
Normative: NotAllowedError is thrown when Permissions Policy disallows web-printing. Chromium additionally throws NotAllowedError for insufficient isolation or a disabled policy, SecurityError where its printing service is inaccessible, and rejects NotAllowedError if the user denies. A detached context throws NotSupportedError in Chromium.
Context and permission
The IDL requires a secure, isolated context. The specification also defines the web-printing Permissions Policy with default allowlist self; Chromium additionally checks an isolated context and cross-origin isolation before getPrinters(). The current proposal requires express, origin-specific consent triggered by enumeration. The exact chooser scope, persistence, and whether a later operation prompts again remain user-agent UX, not a settled web contract.
Lifecycle, cancellation, and cleanup
The algorithm runs in parallel and resolves through the web-printing task source. Consent is initiated here. A returned printer is a handle, not proof that it remains reachable; fetch current capabilities before asking it to print.
Examples
async function listPrinters() {
if (!window.printing?.getPrinters) return [];
try {
return await window.printing.getPrinters();
} catch (error) {
if (error.name === "NotAllowedError") return [];
throw error;
}
}Browser compatibility
| Runtime | Status | Evidence |
|---|---|---|
| Chrome (general) | Proposed and not released. ChromeStatus lists I2S desktop target 147, which is not release proof. Do not infer general desktop Chrome support. | ChromeStatus |
| Current Chromium service | Implemented only when built with IS_CHROMEOS && USE_CUPS; otherwise getPrinters() has no service and throws SecurityError. | Chromium manager implementation |
| Android / mobile | ChromeStatus Android is null; no public mobile release exists. The current ChromeOS+CUPS-only service path does not expose the service on Android. | ChromeStatus; implementation guard |
| Firefox | No signal; no BCD member record found. | ChromeStatus position; BCD API data |
| Safari | No signal; no BCD member record found. | ChromeStatus position; BCD API data |
| webstatus.dev | No feature entry found for this query; this is not proof of absence from browsers. | webstatus query |
Security and privacy
Printer names, IDs, capabilities and state can fingerprint a device and reveal printing activity. A compromised IWA could create unwanted jobs or denial of service. Minimize enumeration and polling, do not expose attributes to untrusted content, validate documents before submitting, and offer an app-level confirmation/audit trail. The spec requires isolation and consent; it does not make printer information non-sensitive.