Pdftools Release Notes

Changed

• HEVC decoding library (libde265) is dynamically linked The libde265 library, which reads HEVC-encoded HEIF images, ships as a separate dynamically linked library. The native library requires the HEIF/HEIC decoding library at load time, even if your application doesn’t use HEIF/HEIC functionality. If Pdftools SDK can’t find the libde265 decoding library, it fails to load. Pdftools SDK includes the required binaries.

Action: After updating, verify that your deployment can still decode HEVC-encoded HEIF images.

Fixed

• Before this update, the Web and MinimalFileSize optimization profiles didn’t downsample or recompress bitonal (scanned black-and-white) images. As a consequence, optimizing a scanned PDF with these profiles produced a file roughly the same size as the input. With this release, these profiles downsample bitonal images and re-encode them with JBIG2. As a result, scanned documents optimize to substantially smaller files.

Changed

• HEVC decoding library (libde265) is dynamically linked The libde265 library, which reads HEVC-encoded HEIF images, ships as a separate dynamically linked library. The native library requires the HEIF/HEIC decoding library at load time, even if your application doesn’t use HEIF/HEIC functionality. If Toolbox add-on can’t find the libde265 decoding library, it fails to load. Toolbox add-on includes the required binaries.
  Action: After updating, verify that your deployment can still decode HEVC-encoded HEIF images.

Fixed

• Before this update, extracting text in C# on Linux dropped or replaced non-ASCII characters in the output. As a consequence, Toolbox add-on returned content with accented or extended Unicode characters incorrectly. With this release, text extraction preserves all UTF-8 characters. As a result, extracted text matches the source document on Linux.

Added

• Viewer users can fill in PDF form fields, toggle checkboxes and radio buttons, type into text boxes, and select options from combo boxes and list boxes. The PDF Web SDK exposes these form fields through the Forms namespace with CheckBoxWidget, RadioButtonWidget, TextBoxWidget, ComboBoxWidget, and ListBoxWidget classes.
• Developers can configure automatic navigation to a PDF’s initial destination using the useInitialDestination option. Set this option in ViewerConfig during initialization or pass it to Document.open(). When enabled, the viewer navigates to the PDF’s initial destination (if defined) when it opens.
• The hidePasswordDialogCancelButton option in ViewerConfig lets developers hide the cancel button in the password dialog. As a result, users must enter a password to proceed.
• New localization methods on PdfToolsViewer enable runtime language management:
  • addLanguage(): adds a new language at runtime.
  • customizeTranslations(): overrides specific translation strings.
  • getAvailableLocales(): lists all available locales.
  • getLocale(): returns the current locale.
  • setLocale(): switches the active locale (supports 'auto' for browser detection).
• The npm package includes third-party open-source license texts in the licenses/ directory. See licenses/MANIFEST.txt for the full list of components.

Changed

• The hideComponents(), showComponents(), and overrideButtonBehavior() methods accept component names instead of path-based references. A type alias provides strict typing for all valid component names.
• The file upload control is disabled while a document is loading, preventing users from uploading another file during the process.
• The viewer preserves the zoom level, fit mode, and page layout when opening a new document.
• The note annotation dialog has an improved layout and full keyboard accessibility.
• The password dialog has an improved layout and full keyboard accessibility.
• The print dialog dots per inch (DPI) selector displays a tooltip explaining each DPI value on hover.

Breaking changes

Localization configuration renamed

The customLocalisationFile configuration option is replaced by customTranslations in ViewerConfig, letting developers provide translation overrides directly in code instead of loading external files. The lang property is replaced by locale, which supports built-in and custom locales, as well as automatic browser detection.

Migration:
Replace customLocalisationFile: 'path/to/file.json' with customTranslations: { en: { key: 'value' } }. Replace lang: 'en' with locale: 'en'.

AnnotationType enum values renumbered

The AnnotationType enum values have shifted to accommodate form widget members (CheckBox 19, RadioButton 20, TextBox 21, ListBox 22, ComboBox 23). Affected values: Screen 19→24, PrinterMark 20→25, TrapNet 21→26, Watermark 22→27, Redact 23→28, 3D 24→29.

Migration:
Use the named enum members (AnnotationType.Redact) instead of raw integer values.

Fixed

• Before this update, printing on mobile devices failed silently or produced blank output when triggered from the print dialog. With this update, the print flow correctly renders document content on iOS and Android devices.
• Before this update, embedding the viewer in CSS flex or grid containers caused layout overflow and scrollbar issues. As a consequence, the viewer did not size correctly within modern CSS layouts. With this update, the viewer respects container constraints. As a result, the viewer displays correctly in flex and grid containers.
• Before this update, running multiple viewer instances on the same page caused style conflicts and rendering errors. With this update, viewer instances are properly isolated. As a result, multiple viewers can run simultaneously on the same page.

Added

• Standard Converter for Office documents With this release, the Conversion Service converts Word, Excel, and PowerPoint files to PDF without requiring a Microsoft Office installation, Microsoft 365 subscription, or Office license feature. The Standard Converter is enabled by default and works on both Windows and Docker deployments. For highest visual fidelity, configure a local Microsoft Office installation or the Office for the web service.
  • The Standard Converter supports the following profile options:
    • Track Changes (Word): Renders revision marks (insertions, deletions, formatting changes) in the converted PDF.
    • Allow Scaling (Excel): Scales worksheet columns to fit on one page.
• Added a Force line break option to preserve Rich Text Format (RTF) line breaks in email text. Generic RTF control-word stripping prevents leftover control characters in the output.
• Added an Include external stylesheets option, separate from Include external images, so you can skip external CSS independently.
• Added missing features to the Configurator Web, reducing the gap with the Windows-based Configurator. Additions include:
  • Signing, Stamping, Annotations, and OCR configuration in profiles.
  • Connector configuration in the Integrations tab for all connector types, including the ability to create connectors and edit existing ones.
• Added a Flatten Form Fields toggle in the Compression and Optimization section of the Configurator profile settings. Turn it on to flatten AcroForm fields into static graphics so that filled-in form values render consistently across PDF viewers. The toggle works in the PDF/A-1, PDF/A-2, and PDF/A-3 workflows. The runtime job option is FLATTEN.FORM.FIELDS. For details, see Compression and optimization settings.

Added

• Dithering control for Fax image conversion The Fax conversion profile exposes a dithering option, letting you switch between dithering modes when rendering PDFs to fax-ready images. For more details, refer to Fax conversion profile.

Fixed

• Before this update, PDF/A conversion incorrectly reported a device-color-space error on documents containing nested form XObjects. As a consequence, valid documents couldn’t be converted to PDF/A. With this release, the converter resolves color spaces correctly. As a result, these documents convert to PDF/A as expected.
• Before this release, optimizing PDFs with certain internal structures caused the optimizer to perform many redundant object comparisons. As a consequence, optimization appeared to hang and didn’t complete on the affected documents. With this release, the optimizer avoids the redundant comparisons. As a result, optimization finishes in the expected time on the affected documents.
• Before this update, validating a malformed PDF containing nested object streams caused unbounded recursion. As a consequence, the process crashed with a stack overflow on the affected documents. With this release, the validator detects the cycle and rejects the document with a clean validation error. As a result, malformed input can no longer crash the validator.

Fixed

• Before this update, Image.Redact() redacted only the base image samples. As a consequence, when an image carried an image mask, the original pixels in the redacted area remained recoverable through the mask stream. With this release, redaction also clears the matching region in the image’s mask stream when present. As a result, the redacted area can no longer be reconstructed from masking resources attached to the same image.
• Before this release, reading a document’s PlainEmbeddedFiles collection (the files attached to a PDF) caused an access violation on certain documents. As a consequence, applications that enumerated embedded files could crash. With this release, the collection is read safely on the affected documents.
• Prior to this update, CheckBox.CheckedExportName returned an empty value for checkboxes created programmatically with CheckBox.Create() after the document was saved and reopened with Toolbox add-on. As a consequence, PDF readers such as Adobe Acrobat displayed a blank export value. With this update, CheckedExportName returns the expected default value Yes after save and reopen.
• Before this update, extracting page content with ContentExtractor and re-appending it with ContentGenerator added an extra layer of graphics-state nesting each time. As a consequence, repeated extract-and-reappend operations pushed the document past the PDF/A nesting limit, and the result could no longer be converted to PDF/A. With this update, ContentExtractor and ContentGenerator no longer add redundant nesting. As a result, repeated extract-and-reappend operations preserve PDF/A convertibility.
• Before this update, opening a malformed PDF containing nested object streams caused unbounded recursion when the affected objects were resolved. As a consequence, the process crashed with a stack overflow on the affected documents. With this release, the loader detects the cycle and reports a clean processing error. As a result, malformed input can no longer crash applications using the Toolbox add-on.

Added

• The Annotation class supports storing custom data through the privateData property of type string. The property persists across save and load cycles, letting applications attach domain-specific metadata to each annotation.
• The Document API emits a pageRendered event when a page finishes rendering. The event payload is the rendered page number.

Changed

• The addAnnotation(), deleteAnnotation(), and updateAnnotation() methods on viewer.document accept either a single annotation or an array of annotations, supporting batch operations with a single call.
• The viewer.document.getPage() method returns a Page synchronously instead of a Promise. Update existing code to call viewer.document.getPage(pageNumber) directly, without await.

Fixed

• Before this update, setting ViewerConfig.devicePixelRatio caused the viewer to crash at browser zoom levels other than 100% because the calculated canvas dimensions didn’t match the rendered buffer. As a consequence, viewer instances that configured devicePixelRatio failed whenever users zoomed the browser. With this update, the viewer derives the effective device pixel ratio from the rendered buffer size. As a result, the viewer renders correctly at any browser zoom level.
• Before this update, text selection under certain circumstances ended one character before the end of the selected word. As a consequence, viewer users couldn’t include the final character when selecting a complete word. With this update, the text-selection logic includes the last glyph in the range. As a result, viewer users can select complete words.

Added

• Viewer users can create ink annotations (freehand drawings) on PDF documents, customize the stroke color, opacity, and line width, erase parts of the drawing, and edit annotations by moving, resizing, locking, or deleting them.
• Developers can set the annotation author using the user option in ViewerConfig during initialization, or the setUser() method on PdfToolsViewer at runtime. The getUser() method returns the configured user. The viewer applies this value when creating or editing annotations.
• The document.addAnnotation() method lets developers add annotations to PDF documents programmatically.
• Developers can configure the device pixel ratio (DPR) using the devicePixelRatio option in ViewerConfig to balance rendering sharpness and performance. Higher values increase sharpness, while lower values improve performance.
• Viewer users can navigate sidebar panels with the keyboard, move the focus between elements using the Tab key, navigate menu items with the arrow keys, and activate buttons with the Enter or Spacebar keys.

Changed

• The viewer.initialize() method throws an error when called on an already initialized viewer instance. Developers must dispose of the existing instance before reinitializing. Use viewer.addEventListener("PdfTools.viewer.initialized") to detect when initialization completes.
• Updated embedded fonts for improved license compliance.

Fixed

• Before this update, the lock/unlock button in the sticky note modal didn’t reflect the current annotation state. With this update, the button stays synchronized with the contextual menu.
• Before this update, viewer users couldn’t create redaction annotations on touchscreen devices. This has been resolved.
• Image upload validates file types and prevents viewer users from selecting unsupported formats.
• The thumbnail panel displays equal left and right margins.
• Redaction annotations are included when saving documents as FDF.

Added

• OCR pre-processing for PDF workflows. Apply OCR to scanned PDFs and images through Pdftools SDK workflows (PDF to PDF/A conversion, conformance validation, digital signing). Connect to an OCR service endpoint to perform recognition without changing application logic. For more details, refer to OCR.

Fixed

• Before this update, certain conversion events, such as XMP metadata information loss, weren’t tracked through the Pdftools SDK error reporting during PDF/A conversion. As a consequence, applications using the SDK didn’t receive these error flags, and conversion issues could go unreported. With this release, conversion event tracking is consistent across all usage paths, and XMP metadata-related errors are properly reported.
• Before this update, generated API interface event handlers didn’t release resources correctly. As a consequence, applications experienced increasing memory consumption over time. With this release, event handlers release resources as expected.

Added

• ForbidImplicitUpgrade option on ConversionOptions to prevent automatic PDF/A conformance level upgrades during conversion.

Changed

• HEIF/HEIC codec library dynamically linked

  The native library requires the HEIF/HEIC decoding library at load time, even if your application doesn’t use HEIF/HEIC functionality. If the decoding library isn’t found, the native library fails to load. The required binaries are included in the distribution, but ensure your service, container layout, library search paths, and permissions allow the library to be found.

  Action:
  After updating, verify that your deployment loads correctly even if HEIF/HEIC processing is not used.

• JBIG2 decoding update

  The JBIG2 decoding implementation has been replaced. JBIG2-encoded images render identically, but error messages related to JBIG2 processing may differ from previous versions.

  Action:
  If you process PDFs with JBIG2-encoded images, consider validating against a representative document set.

• Updated font substitution for missing fonts (including PDF/A)

  When PDFs reference fonts that aren’t embedded and are unavailable on the host, the software substitutes fallback fonts. The updated fallback fonts support a larger glyph set and better fitting to original glyph dimensions. Layout should remain stable, but visual appearance differs from both the original font and previous versions.

  Action:
  If exact reproduction is required, install the original font in your environment.

• ZapfDingbats font delivery change

  ZapfDingbats is no longer shipped. The fallback font URW++ D050000L.ttf is used instead, but it doesn’t provide full coverage and may differ slightly in appearance.

  Action:
  If exact ZapfDingbats reproduction is required, install the font in your environment.

• Refreshed internal mapping tables

  Character mapping tables used for Unicode and glyph mapping have been updated. Changes are primarily additive (new code points) with occasional correctness fixes.

• Java: native library loaded automatically

  Before this release, Java applications had to explicitly locate and load the Pdftools SDK native binary using System.load() or System.loadLibrary() before calling any SDK function. With this release, the native binary is loaded automatically at runtime.

  The Maven dependency has also been simplified: the platform-specific native artifact classifier is no longer needed.

  Action:
  Remove any System.load() or System.loadLibrary() calls for the Pdftools SDK native library from your code. In your code pom.xml , replace the two-dependency block (main JAR + native artifact) with a single dependency on pdftools-sdk . Refer to the Java getting started guide for the updated configuration.

• Upgraded libxml2 from version 2.10.3 to 2.15.0. Error messages related to XML processing may differ from previous versions.

Fixed

• Debug-level log messages are written to the file output sink when file logging is configured via PDF_TRACE_OUTPUT or PDFT_LOG_OUTPUT.
• Fixed a crash when repairing PDFs with XMP metadata dates missing timezone information.
• PDF/A conversion no longer fails when the document contains a /Tabs entry written as a string instead of a name object.
• PDF/A conversion no longer fails when the document contains a CIDFont dictionary without a /Type entry.
• The remove-PieceInfo option (eStripPieceInfo ) also removes PieceInfo dictionaries from XObject resources.
• Before this update, on Linux, PDF dates were computed using the UTC offset of the current time instead of the UTC offset applicable to the date being processed. As a consequence, PDF dates could be off by one hour when the document’s date and the current time fell in different daylight saving time (DST) periods. With this release, the UTC offset is correctly derived from the date being processed.
• Before this update, the JBIG2 decoder placed no limit on memory allocations, which could cause excessive memory consumption when processing PDFs with malformed or unusually large JBIG2-encoded images. With this release, JBIG2 memory allocation is capped at 2 GB.
• Before this update, calling Extractor.ExtractText() using the C# binding on Linux produced incorrect output. As a consequence, non-ASCII UTF-8 characters were silently dropped from the extracted text. With this release, text extraction produces correct UTF-8 output on Linux.

Added

• Enhanced logging configuration environment variables:
  • PDFT_LOG_OUTPUT for output control, replacing PDF_TRACE_OUTPUT. The PDF_TRACE_OUTPUT also remains supported for backward compatibility.
  • PDFT_LOG for log level filters. The comma-separated format: *:error,libbase:info , where * sets the default level.

Changed

• Switched from the zlib to zlib-ng library, significantly improving performance when compressing and decompressing Flate streams by using SIMD instructions.

Fixed

• Corrected conformance retrieval logic in the GetConformance method to properly handle invalid ConversionOptions values.
• Certificate loading on Windows now includes Local Machine store in addition to Current User store, resolving certificate access issues for Internet Information Services (IIS) applications running under service accounts.
• Widget annotation appearance generation now correctly checks for rich text value (RV) entry instead of rich text style (DS) entry when determining whether to create appearance streams.

Fixed

• Resolved an issue using an uninitialized variable that could cause unpredictable behavior during PNG processing.
• Fixed a stack buffer overflow when creating annotation appearances.
• Corrected glyph position problems caused by improper handling of adjustment values.
• Ensured the GTS_PDFX output intent is correctly copied into the output document to maintain PDF/X compliance. The GTS_PDFX defines the standardized printing output intent for PDF/X files.
• Fixed an infinite loop that could occur during optimization for specific malformed PDF files.
• Addressed an access violation related to cross-reference (xref) tables, preventing potential crashes.

Added

• Added IsFullRevisionCovered flag to signature validation results to detect partial ByteRanges.

Changed

• Removed library load/unload messages from Python bindings.

Fixed

• Font name decoding for Type0 fonts on Linux and macOS to preserve Unicode characters.
• Malformed import in native_base.py that caused errors in Python bindings.
• Fixed error reporting for non-UTF8 colorant name on Linux and macOS.
• Font name decoding on Linux and macOS to align behavior with Windows.
• Fixed unexpected termination when processing image dictionaries with an empty /Filter array.
• Removed stray null terminators from strings returned by the Python interface.