Some test text!


Get started

Quick start - view a documentDownload PDFTron SDKIntegrate with GradleIntegrate manuallyRun samplesAdd license keyUpdate to latest versionTroubleshooting


System requirementsDocument lockingDocument savingRun project in Android StudioRun project with source codePDFTron full vs. standardReduce size of APK

Document Viewer

OverviewShow a document in an ActivityShow a document in a FragmentViewer configurationToolManager configurationDay and Night themesOpen from online URL

Document Viewer components

OverviewPDFViewCtrlReflowQuick menuCustomize quick menuAnnotation toolbarAnnotation style editorCustomize annotation style editorPage sliderList containerAnnotation listDocument outlineUser bookmark listThumbnail browserAdd pages dialogCrop pages dialogRotate pages dialogView mode dialog

Annotation and collaboration

OverviewRead only modeDisable annotation creation and editingDefault annotation propertiesChange tool modeEventsOverride annotation handlingShow and hide existing annotationsUndo and redoRealtime collaboration

Advanced customization

OverviewAdd a custom view to a pageCreate a custom toolPage coloring modePage fit modePage layout modeScrolling directionRight-to-left support


Convert documents to PDFConvert HTML to PDF

Parsing and extraction

Text extraction

Digital signatures



Text search

Advanced topics

PrintUnderstand coordinatesGenerate page thumbnailsChange annotation propertiesDelete annotationsTool class hierarchy

Other frameworks



Multidex build errorReduce memory consumptionDetachCurrentThread warning



PDF Processing API

What is PDFNet?Opening a documentSerializing (saving) a documentWorking with pagesWorking with Page ContentWorking with BookmarksWorking with Interactive Forms (AcroForms)PDF SecurityLow-level PDF APIError handling
Text extractionkeyboard_arrow_down

Text extraction using PDFTron SDK

In this document
chevron_rightExtracting text data from a PDF document
chevron_rightText runs
chevron_rightTextExtractor class

linkExtracting text data from a PDF document

When we use the ElementReader class to read elements from a PDF document, we are often faced with data that is partial. For example, let us say that we are attempting to extract a sentence that says "This is a sample sentence." from a PDF document. We could potentially end up with two elements - "T" and "his is a sample sentence.". This is possible because in a PDF document, text objects are not always cleanly organized into words sentences, or paragraphs. The ElementReader class will return Element objects exactly as they are defined in the PDF page content stream.

linkText runs

An element of type e_text directly corresponds to a Tj element in the PDF document. Each e_text element represents a text run, which represents a sequence of text glyphs that use the same font and graphics attributes. Say, if there is a single word, whose letters are each presented with a different font, then each letter would be a separate text run. You may also encounter text runs that contain multiple words separated by spaces. The PDF format does not guarantee that the text will be presented in reading order.

linkTextExtractor class

All this just goes to say that attempting to use an ElementReader to extract text data from a PDF document is not guaranteed to return data in the order expected (reading order). The most straightforward approach to extract words and text from text-runs is using the pdftron.PDF.TextExtractor class, as shown in the TextExtract sample project - TextExtract Sample

TextExtractor will assemble words, lines, and paragraphs, remove duplicate strings, reconstruct text reading order, etc. Using TextExtractor you can also obtain bounding boxes for each word, line, or paragraph (along with style information such as font, color, etc). This information can be used to search for corresponding text elements using ElementReader.