Opening the Chrome Developer Tools console
The Chrome browser console is a text window built into Chrome that shows you messages from websites and lets you run commands. To open it, press Ctrl+Shift+J on Windows or Linux, or Cmd+Option+J on Mac. The console will appear as a panel at the bottom or side of your browser window.
If those keyboard shortcuts do not work, you can open it through the menu instead. Click the three vertical dots in the top right corner of Chrome, select "More tools", then click "Developer tools". A panel will open on the right side of your screen. At the top of that panel, click the "Console" tab to see the console specifically.
The console stays open until you close it. You can close it by pressing the same keyboard shortcut again, or by clicking the X button in the top right corner of the developer tools panel.
Key Takeaways
- Press Ctrl+Shift+J (Windows/Linux) or Cmd+Option+J (Mac) to open the console when ready.
- If keyboard shortcuts do not work, use the Chrome menu: three dots → More tools → Developer tools, then click the Console tab.
- The console shows error messages and warnings from the website you are viewing, which helps you understand what went wrong.
- You can type commands directly into the console to test code or inspect how the page works.
What you see in the console window
When you open the console, you will see a text area with a blinking cursor at the bottom. Above that are messages from the website, usually in different colors. Blue or black text is normal information. Yellow text with a warning icon means something unexpected happened but the page still works. Red text with an X means an error — something broke.
Each message shows where in the website's code the problem occurred. If you click on the file name or line number, Chrome will show you the actual code. This is useful if you are trying to understand why a website is not working the way you expect.
At the very top of the console, you might see a message that says something like "This appears to be a staging environment" or a warning about pasting code. These are normal and do not mean anything is wrong with your browser.
Running commands in the console
The console is not just for reading messages — you can also type commands into it. Click in the text area at the bottom where the cursor is blinking, type a command, and press Enter. The console will run that command and show you the result on the next line.
For example, if you type document.title and press Enter, the console will show you the title of the current webpage. If you type 2 + 2 and press Enter, it will show you 4. These are straightforward examples, but the console can run much more complex code if you know how to write it.
If you make a mistake or want to run a command you typed before, use the up and down arrow keys to scroll through your command history. This saves you from typing the same thing twice.
Common reasons to open the console
Web developers open the console to find out why a website is not working. If a page loads slowly, shows broken images, or buttons do not respond when you click them, the console often contains error messages that explain what went wrong.
You might also open the console if someone asks you to check for errors when you report a problem to a website's support team. Many support pages will ask you to "check the console for errors" and copy any red text you see there. This gives the developers information they need to fix the problem.
If you are learning to write code, the console is also a place to test small pieces of code before you use them in a real project. You can experiment with commands and see the results when ready.
Clearing the console and managing messages
If the console fills up with many messages and you want to start fresh, type clear() in the console and press Enter. All the old messages will disappear, and you will have a blank console again. This is useful if you are testing something and want to see only the new messages.
You can also filter messages by type. At the top of the console panel, you will see buttons or a dropdown that says "All messages", "Errors", "Warnings", or "Info". Click one of these to show only that type of message. For example, clicking "Errors" will hide warnings and info messages so you can focus on what broke.
If a website is sending too many messages to the console and it is hard to read, you can right-click on a message and select "Hide messages from [website name]" to silence that particular source.
Console settings and customization
The console has a few settings you can change. Click the gear icon in the top right corner of the developer tools panel to open settings. Under the "Console" section, you can turn on "Log XMLHttpRequests" to see network requests the page makes, or turn on "Eager evaluation" to see results as you type commands.
You can also change where the developer tools panel appears. By default it opens at the bottom of your screen, but you can move it to the right side, the left side, or even open it in a separate window. Click the three dots menu in the top right of the developer tools panel and look for "Dock side" options.
Most of these settings are optional. The default setup works fine for most people, and you only need to change them if you find the console hard to read or want a different layout.
Frequently Asked Questions
Why does the console show red error messages when the website looks fine?
Websites sometimes have errors that do not affect what you see on the page. A missing image file or a broken tracking script might show a red error in the console but not break the website itself. You only need to worry about console errors if the website is actually not working the way it should.
Is it safe to paste code into the console?
Only paste code from sources you trust. If someone online tells you to paste code into the console, make sure you understand what it does first. Malicious code pasted into the console can access your passwords or personal information on that website. Chrome shows a warning about this when you open the console to remind you.
Can I use the console on websites other than the one I am viewing?
No. The console only shows messages from and runs commands on the website currently open in that tab. Each tab has its own separate console. If you open a different website in a new tab, you need to open the console in that tab to see its messages.
What does "undefined" mean when I run a command?
Undefined means the command ran but did not return a value. This is normal for many commands. For example, if you type a command that changes something on the page, it might show "undefined" instead of a result. This does not mean anything went wrong.
Can I save the messages from the console?
You can copy messages by selecting the text and pressing Ctrl+C (or Cmd+C on Mac), then paste them into a text file. Some browsers also let you right-click on a message and select "Save as" to read the console output, though this varies by Chrome version.