Using the Console

By Kayce Basques

Technical Writer at Google

By Andi Smith

Andi is a contributor to WebFundamentals

By Meggin Kearney

Meggin is a Tech Writer

By Paul Bakaus

Open Web Developer Advocate at Google • Tools, Performance, Animation, UX

Learn how to: open the DevTools Console, stack redundant messages or display them on their own lines, clear or persist output or save it to a file, filter output, and access additional Console settings.

TL;DR

• Open the Console as a dedicated panel or as a drawer next to any other panel.
• Stack redundant messages, or display them on their own lines.
• Clear or persist output between pages, or save it to a file.
• Filter output by severity level, by hiding network messages, or by regular expression patterns.

Opening the Console

Access the Console as a full-screen, dedicated panel:

Or as a drawer that opens next to any other panel:

Open as panel

To open the dedicated Console panel, either:

• Press Ctrl+Shift+J (Windows / Linux) or Cmd+Opt+J (Mac).
• If DevTools is already open, press the Console button.

When you open the Console panel, the Console drawer collapses automatically.

Open as drawer

To open the Console as a drawer next to any other panel, either:

• Press Esc while DevTools is in focus.
• Press the Customize and control DevTools button and then press Show console.

Message stacking

If a message is consecutively repeated, rather than printing out each instance of the message on a new line, the Console "stacks" the messages and shows a number in the left margin instead. The number indicates how many times the message has repeated.

If you prefer a unique line entry for every log, enable Show timestamps from the DevTools settings.

Since the timestamp of each message is different, each message is displayed on its own line.

Working with the Console history

Clearing the history

You can clear the console history by doing any of the following:

• Right-click in the Console and press Clear console.
• Type clear() in the Console.
• Call console.clear() from within your JavaScript code.
• Type Ctrl+L (Mac, Windows, Linux).

Persisting the history

Enable the Preserve log checkbox at the top of the console to persist the console history between page refreshes or changes. Messages will be stored until you clear the Console or close the tab.

Saving the history

Right-click in the Console and select Save as to save the output of the console to a log file.

Selecting execution context

The dropdown menu highlighted in blue in the screenshot below is called the Execution Context Selector.

You'll usually see the context set to top (the top frame of the page).

Other frames and extensions operate in their own context. To work with these other contexts you need to select them from the dropdown menu. For example, if you wanted to see the logging output of an <iframe> element and modify a variable that exists within that context, you'd need to select it from the Execution Context Selector dropdown menu.

The Console defaults to the top context, unless you access DevTools by inspecting an element within another context. For example, if you inspect a <p> element within an <iframe>, then DevTools sets the Execution Context Selector to the context of that <iframe>.

When you're working in a context other than top, DevTools highlights the Execution Context Selector red, as in the screenshot below. This is because developers rarely need to work in any context other than top. It can be pretty confusing to type in a variable, expecting a value, only to see that it's undefined (because it's defined in a different context).

Filtering the Console output

Click the Filter button () to filter console output. You can filter by severity level, by a regular expression, or by hiding network messages.

Filtering by severity level is equivalent to the following:

Additional settings

Open the DevTools settings, go to the General tab, and scroll down to the Console section for further Console settings.