Compress PowerPoint files quickly and reliably

Microsoft PowerPoint files often contain lots of content that can be compressed; from oversized images and old fast save information to hidden data in embedded objects. NXPowerLite can selectively optimize each of these elements within the files to create leaner, smaller presentations.

Resize images in PowerPoint

Images are often inserted into Microsoft® PowerPoint presentations at much larger sizes than necessary. For example, a photograph taken by a digital camera might contain ten million or more pixels, but most of this detail will not be visible unless ‘zoom’ controls are used. NXPowerLite can scale down such images by a configurable amount. For example, if NXPowerLite is configured to optimize PowerPoint® files for viewing at 1600x1200 pixels (the default setting), any images which fill an entire slide and are larger than 1600x1200 pixels will be scaled down to 1600x1200 pixels (sufficient for nearly all viewing and printing purposes).

You may also like how to find large images in PowerPoint, which shows you how to identify and jump to any large images using the Slidewise PowerPoint add-in.

JPEG conversion & compression

NXPowerLite can convert certain types of image to JPEG format, which offers high compression levels but can affect image quality. NXPowerLite can also apply additional compression to images that are already in the JPEG format. The default setting (7) will result in a barely noticeable loss of quality, even at 100% zoom.

Metafile conversion

PPTX files often contain images in WMF (‘Windows Metafile’) and EMF (‘Enhanced Metafile’) formats, which are suitable for vector graphics but are highly inefficient for representing bitmapped images (e.g. screenshots or photographs). Wherever possible, NXPowerLite will convert such images to PNG or JPEG format depending on which is smaller.

Flatten embedded charts in PPTX

When you insert a chart into PowerPoint from Excel, by default you end up with a complete copy of the Excel file saved inside your presentation. This happens each time you paste a different chart in. NXPowerLite can remove the Excel files from your deck, leaving just the chart behind. Great for ensuring you don’t accidentally share any sensitive data and also reducing file size.

Flattens embedded objects

Embedded objects (e.g. an Excel® chart embedded in a PowerPoint® presentation) are saved in Microsoft® Office documents with two representations - a 'picture' representation and a 'native' representation. If NXPowerLite is configured to flatten embedded objects, it will remove the 'native' representation, which can significantly reduce the size of files, but flattened objects can no longer be edited in the application in which they were created.

To edit embedded objects manually, read about how to find objects and charts in PowerPoint using Slidewise.

Removes cropped areas of inserted images

After inserting an image into a PowerPoint slide, it is possible to request that the image be 'cropped'. This option is available by right-clicking on an image and selecting 'Size and Position...' in Office 2007 or later, or 'Format Picture...' in earlier versions of Office. Cropping causes only part of the image to be displayed, although the entire image is preserved when the file is saved, so it is possible to undo or change the amount of cropping later. If NXPowerLite is configured to discard cropped image data, the non-visible parts of images will be removed, so will not be recoverable after optimization.

Removes "fast save" information

PowerPoint® 2003 and earlier have the option to enable 'Fast saves'. This has the effect that in some cases, deleted or edited objects will not be removed from the PowerPoint® file when changes are saved. NXPowerLite removes this 'fast save' information, preserving only the most recent edit. Previous edits are not available through PowerPoint’s® user interface anyway, but forensic tools may be able to extract some historical information from a ‘fast saved’ file.

Removes unnecessary metadata

Some image file formats (e.g. PNG or JPEG) allow additional metadata to be embedded in the image file. For example, JPEG files created by a digital camera may contain EXIF information which indicates the type of camera used, where the photograph was shot and date that it was taken. NXPowerLite removes any data which is not required to display the image.