การอ่านไฟล์ PDF ใน Firefox
Firefox includes a built-in PDF viewer to display PDF files inside the browser window. This article explains how to use the built-in PDF viewer, how to use another PDF viewer and how to fix the common issues you might encounter.
Table of Contents
Using the built-in PDF Viewer
Firefox includes a built-in PDF viewer that allows you to view almost all PDF files found on the web without a plugin. The built-in PDF viewer is enabled by default.
PDF Viewer toolbar functions
- View document thumbnails or outline - The slider button on the far left will open a sidebar with thumbnails of the document's pages. Some documents will also have an outline view available. These make it easy to navigate through a long document.
- Page up and down or skip directly to a page - You can use the up and down arrows to page through a document or enter the number of the page you want to go to.
- Change the size of the document - Use the + and - buttons to zoom in and out or choose a zoom setting from the dropdown menu.
- Fullscreen or Presentation mode - Click the fullscreen button to allow the PDF file to take over your entire screen. Press ESC to exit fullscreen mode.
- Print - Click the Printer button to open the print setup dialog.
- Download - Click the Download button to save the PDF file to your computer or to open it with a PDF reader program.
- Copy current view - Right-clickHold down the Ctrl key while you click
the current view button to open the current view in another tab or window.
PDF Viewer keyboard shortcuts
|Next page||N or K or →|
|Previous page||P or J or ←|
|Zoom in||Ctrl + +command + +|
|Zoom out||Ctrl + -command + -|
|Automatic Zoom||Ctrl + 0command + 0|
|Rotate the document clockwise||R|
|Rotate counterclockwise||Shift + R|
Troubleshoot problems with the PDF viewer
- With certain types of PDF files, the PDF Viewer may have problems displaying fonts, colors or the whole document. If some PDF files don't render well or are blank, click the download button on the right side of the document header to open it with the default PDF viewer application on your computer.
- If you can't open any PDF files with the built-in PDF viewer, a Firefox extension could be the cause. You can disable all your extensions, to see if one of them was the problem. For details, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.
Using another PDF viewer
You can use a different PDF viewer instead of the built-in PDF viewer, if you prefer. To change from using the built-in PDF viewer to another PDF viewer:
- Click the menu button and choose . .
- Select the panel.In the panel, navigate to the Applications section.
- Find Portable Document Format (PDF) in the list and click on the entry to select it.
- Click on the drop-down arrow in the Action column for the above entry. The Action entry will show Preview in Firefox when you're using the built-in PDF Viewer.
- To use an external application to view PDF files, select the entry for the PDF application you wish to use, such as Use Preview or Use Adobe Reader. Warning: The "Adobe Acrobat NPAPI Plug-in" has been known to cause problems in Firefox. See PDF files are blank or cause an error message on Mac for details.
- To use an available plugin to view PDF files in Firefox, select Use PDF plugin name (in Firefox).
Using a PDF viewer plugin
You can use a PDF plugin like Adobe Acrobat, Nitro PDF Reader or Sumatra PDF like Adobe Acrobat, MozPlugger, or KParts plugin, if one is available, to view PDF files in Firefox. If you have installed a PDF viewer plugin but you have problems using it in Firefox, try these solutions:
Enable the PDF plugin
Your PDF plugin may be disabled in Firefox. To enable it:
Click the menu button and choose . The Add-ons Manager tab will open.
- In the Add-ons Manager tab, select the panel.
- Select your PDF plugin.
- Select in its drop-down menu.
Reset download actions
Open your profile folder:
Click the menu button , click help Click the menu button , click and select . The Troubleshooting Information tab will open.
Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
- Under the Application Basics section, click on A window will open that contains your profile folder.Your profile folder will open. .
Click the menu button and then click ExitQuit .
Click the Firefox menu , then click .Click the Firefox menu at the top of the screen, then click .Click the Firefox menu , then click .
- Delete (or rename) the mimetypes.rdfhandlers.json file.
- Re-initialize the plugins database. Follow the instructions in Re-initializing the plugins database.
- If the PDF plugin comes bundled with an application, check the application preferences, to see if there is an Internet setting to enable the plugin or to display PDF files in the browser.
- If the PDF plugin comes bundled with an application, uninstall and re-install the PDF application. If the PDF application is Adobe Reader, uninstall all versions of Adobe Reader from your computer (see Adobe's instructions for uninstalling for Reader versions 8 and above) and then reinstall the latest version from Adobe's download page. If you still can't view a PDF file in Firefox with the Adobe PDF plugin, see the Adobe help page, Troubleshoot viewing PDF files on the web.