---
id: "navegador-tamanhos-e-emulacao"
titulo: "Sizes, emulation and location"
resumo: "Test the page at other screen sizes, emulate devices, network and CPU, and override geolocation."
idioma: "en"
tipo: "guia"
categoria: "telas"
aplicavelDesde: "0.0.16"
capabilities: ["browser.viewport", "browser.emulation", "browser.geolocation"]
estadoEditorial: "aprovado"
nivelEvidencia: "artefato-distribuido"
refFonte: "27574c339b58316408f6be2d62169d59041d07bf"
revisaoFonte: "2026-09-24"
revisor: "mantenedor (v1, 2026-10-03)"
rota: "/docs/en/ferramentas/navegador/tamanhos-e-emulacao/"
fonte: "pt-br/ferramentas/navegador/tamanhos-e-emulacao.md"
caminhoPublico: "docs/publica/en/ferramentas/navegador/tamanhos-e-emulacao.md"
hashFonte: "sha256:786bd26103bc0956fceba039a80ff8946a165c6734f1256d2d17946d6ddbea80"
hashDestaPagina: "sha256:e96a80bd0519dc8e736fcafae8a7fa5d68d588faed7d0ef4d29703a56651dc22"
traducaoAssistidaPorIA: true
traducaoDesatualizada: false
corpoRetido: false
---
<!-- traducao-assistida-por-ia: idioma=EN fonte=pt-br/ferramentas/navegador/tamanhos-e-emulacao.md fonteHash=sha256:786bd26103bc0956fceba039a80ff8946a165c6734f1256d2d17946d6ddbea80 estado=atual -->

Three adjustments that change the environment in which the page sees itself: the screen size, the network and processing conditions, and the reported geographic position.

## Viewport sizes

- In the **toolbar** there is a device group that applies a size preset.
- In the **three-dot menu** there is the size list, with presets covering from small phone to large laptop, including tablet.
- The chosen preset **is remembered per tab** — each tab has its own.

A hand-set size is also possible, with width, height, scale and mobile mode.

> **A viewport override hides the real layout until it is removed.** If the page looks odd after a test, confirm whether a size is still applied to that tab.

## Device, network and CPU emulation

From the command line you can apply emulations that go beyond size:

| Emulation | What it does |
|---|---|
| **Device** | Applies a known device to the tab |
| **CPU** | Applies processing throttling, with an integer rate greater than or equal to 1 |
| **Network** | Applies a network condition: `slow-3g`, `fast-3g`, `slow-4g`, `fast-4g`, `offline` or `no-throttling` |
| **Offline** | Turns offline mode on and off |
| **Media preferences** | Sets color scheme and reduced-motion preference |

The network emulation result **prints the effective rates applied** — that is what lets you state what was emulated instead of assuming it.

**Reset clears CPU and network at once.** If you emulated a network to measure something, **reset before the next measurement**: forgotten throttling contaminates the next number.

## Geolocation

Geolocation overrides the position reported to the page. You must provide latitude and longitude; accuracy is optional.

> **A fake position changes what the page shows and what it may consent to.** Regional content, notices and consents can react to the position — including in ways you do not want recorded on a real account.

## Limits

- The emulation applies **per tab** and lasts while it is applied.
- The viewport override and the emulation **do not** change the app window: they change what the page thinks the screen is.
- The effective rates and conditions must be read from the command's output — there is no promise that the machine can reproduce exactly the requested condition.