To get a printer online on a Mac, the most effective steps are:

1. **Check Printer Status and Resume Printing**
Go to **System Preferences > Printers & Scanners**, find your printer, and if it shows “Offline,” right-click (or Control-click) the printer and select **Resume** to bring it online[1].

2. **Ensure Proper Connection**
Confirm the printer is properly connected to your Mac:
– For USB: Check the cable is securely plugged into both devices.
– For wireless: Make sure the printer and Mac are connected to the *same* Wi-Fi network[2][5].

3. **Set Printer as Default**
In **Printers & Scanners**, select your printer and click **Set as Default Printer** to route all print jobs properly[1][5].

4. **Clear Print Queue**
If print jobs are stuck, clear the queue by selecting the printer, clicking “Open Print Queue,” highlighting pending jobs, and canceling them[1][3].

5. **Reset Printing System** (if issues persist)
In **Printers & Scanners**, right-click the printer list and choose **Reset Printing System** to remove and reset all printers, then re-add your printer[1][4][5].

6. **Update or Reinstall Printer Drivers**
Download and install the latest drivers from your printer manufacturer’s website, then reinstall the printer on your Mac[1][2].

7. **Check Firewall and Network Settings**
Occasionally, firewall settings or network conflicts prevent printer communication; check and adjust these settings as needed[1][5].

These steps apply generally to most printers, including Brother, Canon, and HP models. If after trying these your printer still shows offline, consult printer-specific support or firmware updates[1][4][5].