Edit PDF Files

jPDF Tweak is a simple Java-based tool that lets you modify PDF files by customizing them with watermarks, re-arrange the bookmarks, or change the page size. Password protection is also available in this nifty lightweight instrument, as well as personalizing how a PDF file is opened in your default reader.

The application is free of charge and you will need Java Runtime Environment installed on the computer in order to benefit from its advantages. No installation is required to use it, just unzip and execute the JAR file.

If you expect jPDF Tweak to come wrapped up in a shiny pretty interface, it is not the case. Looks are overshadowed by functionality in this case. A simple window containing a set of 11 tabs all filled up with various options is all you will get.

You can merge multiple documents into a single file and choose the pages you want to include in the final result; this can be done either by automatically selecting the odd or even pages, or by manually imputing the page interval you need. In this case you will only deal with the first and the last tab of the applet window.

Rotating pages and turning them from landscape to portrait is no tough job for the applet. It also features options for scaling the pages either to a preset size or to a custom one. For the latter choice the measurement is done in PostScript points. One PostScript point is the 72nd part if an inch.

The applet lets you personalize the documents with a watermark of your choice. This can be either the first page of a different PDF file displayed in the background, or a transparent text string you punch in (whose opacity and font size you control) shown across each and every page.

Another option is to add page numbers as a watermark. These can be placed anywhere on the page (horizontal and vertical position is calculated in PostScript points).

The toughest nut to crack in jPDF Tweak is the page shuffling tab. The options work fine, but in our case they proved to be a pain to configure them in a way to mix up the pages the way we wanted. It took us a long time to figure out the mysterious ways the algorithm works in, but we managed to prevail with persistence, the applet’s help manual and the preview screen.

Preset configuration is available in this tab, and, as the developer suggests in the manual, if you find a preset that works for you, stick with it. On the other hand, you will miss out on the powerful function in the application.

For the users unwilling to put some time into understanding how page shuffling works it would be nice if the applet came with an interactive preview window that would let you set the page offset values by simply dragging the page into the right position.

The applet also sports a tab for modifying the page numbers. It lets you change the start page, the style, and even add a prefix. The modifications made here have no visible effect on the document’s pages themselves. These come in useful, though, when jumping from page to page.

Some documents have the first pages numbered with Roman numbers. This turns into a problem when you want to jump to a specific page because you will be taken ahead your target by the exact number of pages as are numbered with Roman numbers. This tab lets you modify this so that jumping to a different page actually lands you on the exact page you wanted.

Bookmarks in your PDF are also subject to change. jPDF Tweak allows you to define a new set of bookmarks by typing in the depth, page number or title. Text formatting options are also available. The best part is that you can import the bookmarks of the loaded document, or a different PDF or CSV file.

Everything works fine as long as you do not forget to add the position of the first bookmark. Our tests included both older documents as well as newer ones, and the result was a success all along.

jPDF Tweak is slick enough to let you attach files to your PDF. You can do this under “Attachments” tab. That’s the spot from where you can manage all the additional data glued to the document. One aspect that needs to be mentioned is that none of the attachments added to the original document can be viewed with jPDF; for this you will have to use your default PDF viewer. This means that once you reload a PDF after restarting the applet, no attachment will be visible.

The most appealing tab in the program is “Interaction”. It provides the means to pre-configure how a PDF file is displayed once it is accessed. Moreover, you can add transition effects when a page is turned automatically.

One transition effect can be applied to multiple pages or you can use all 16 transitions in the process. The duration of the effect display as well as of the page is also in the hands of the user. You can adjust the number of seconds you want each of them to be shown on the screen.

“Interaction” tab is more powerful than this, however. On top of the “slideshow” feature it also offers the possibility to configure how the document is opened in the PDF viewer. You can select to hide various elements of the interface, choose a different page layout or page mode from the presets available.

Changing document’s info is also among jPDF Tweak’s set of tricks. But this endeavor will not be successful with all documents. Older ones will remain unaffected by your effort to modify the author or producer. We managed to modify the document information on files saved as PDF with Microsoft Word 2010.

If your documents are unprotected, jPDF is perfectly capable of adding an owner password or even a user countersign to prevent the curious from peeking inside. The encryption used is not exactly top notch, but you can count on AES-128 bit algorithm to guard the information.

Signing the file and setting permissions are two other advantages jPDF Tweak puts on the table. Signing is a serious deal that requires a key and a certificate. If you do not have these, document manipulation permissions are all that’s left for you to define.

jPDF Tweak will not work flawlessly. We bumped into some snags during our tests, but it is definitely worth taking a look at, especially if you work with PDF files.

The Good

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The Truth