ComPDFKit PDF SDK includes the following key features:

• Viewer - Maintain a smooth viewing experience in even the most complex PDF documents with fast and battle-tested rendering engine. Providing solutions to accommodate a fully customizable UI with powerful PDF APIs.
• Annotation - Markup PDFs with highlights, stamps, and comments, draw and add notes to PDFs, or create custom annotations, each with its own style controls. Bring users an excellent reading and writing experience, import and export is also available.
• Signature - Apply electronic and digital signatures in PDFs to trace and speed up signing workflows. Certify, and validate certificate-based documents you receive.
• Forms - Easily create PDF forms. By supporting fillable AcroForms, XFA, and non-interactive forms, your users can view, fill from fields, edit, and save forms with ease.
• Document Editor - Embed document manipulation and page editing tools to split , extract, and merge PDFs, making it easy to add, reorder, duplicate, rotate, crop, and delete pages.
• Edit PDF - Automatically detect font and size of the original text content. Easily update PDF documents by changing text and images.
• Security - Expand beyond basic encryption password and permission settings to protect PDF documents. Included are sensitive information redaction, customized watermarks, and much more.
• PDF to PDF/A - PDF/A converter is an extremely convenient function to make sure you can open files regardless of how many years go by. It enables to convert scanned PDF to searchable text(OCR required) for indexing and archiving legacy and paper documents. Besides all documents which are fully compliant with current ISO archiving standards.

Key Features

Viewer

• Display Modes:
  • Continuous scroll for the vertical direction.
  • Single-page or double-page view for the vertical direction.
  • Automatically trim PDF white margins to resize pages.
  • Support cover mode to show cover page during double page view.
  • Set, delete, and add the space between two pages, adjusting the space before and after a PDF page.
• PDF Navigation:
  • Thumbnails:
    • Get an overview of the content of any part of a document via thumbnails.
    • Set page thumbnails to jump quickly to a linked page or adjust the current viewing page. Allow to move, copy, or delete a PDF page by thumbnails.
  • Outline:
    • Get all details about the outline of a PDF file including the names, links, and the actions like jumping to the link, email, PDF page, etc.
    • Add, move, and delete items/subitems in an outline to display the document’s structure and let users navigate documents in a speedy manner.
    • Edit outlines by renaming them, and resetting their link to a specific page, a web page, or an email address.
  • Bookmarks:
    • Get all information about the bookmarks including the bookmark title, link page, date, etc.
    • Add bookmarks to mark a place in the PDF to any location within the document.
    • Modify a bookmark name and date, and set its destination to a specific page.
    • Delete an existing bookmark from the document.
• Text Search & Selection:
  • Search within an entire document or page range by using a string, match the text exactly, and get the search result.
  • Select a word, phrase, sentence, or entire passage to copy text from a PDF document.
• Zooming:
  • Provide super zoom out and in to unlock more zoom levels.
  • Pinch or double tap on a specific area to perform zoom freely.
  • Make your PDF viewing window adapt to the width of different files, providing a better reading experience.
• Themes:
  • Change theme color and perfectly suit darker reading environments.
  • Set custom colors to display the document to protect eyes after long-time reading like light green, light brown, etc.
• Text Reflow - Rearrange text to fit the device screen size for displaying the same layout.

Annotations

• Annotation Types - Provide a variety of annotation tools (Note, Link, FreeText, Shapes, Markup, Stamp, Ink, Sound, and more) and support adding notes for each annotation tool with a popup window.
• Create & Delete Annotations - Add and remove all supported annotation types easily to mark up key points or add more details.
• Edit Annotations - Powerful editor to modify PDF annotation values and properties, such as font, color, border style, line width, opacity, and more.
• Annotation Appearances - Set and update the appearance of all the annotations automatically.
• Import/Export Annotations - Import existing annotations as XFDF/FDF, or export annotations from PDF to XFDF/FDF for optimizing storage capacity.
• Flatten Annotations - Flatten annotations and burn them into the document as the original content, making a PDF annotation non-editable.
• Annotation Permission - Organize and control all the permissions of annotations like viewing, printing, editing, etc.
• Predefine Annotations - Customize the default properties of all kinds of annotation for personalities.
• Undo/Redo - Undo or redo your processing to annotations like adding, deleting, modifying, or moving.

Forms

• Create & Delete Forms - Allows you to create and delete form fields on PDF documents.
• Form Fields - Support all PDF form fields such as text field, push button, check box, radio button, combo box, list box, signature fields, and barcode (PDF417, QRCode, DataMatrix).
• Form Editor - Move fields around, and adjust form properties to avail of a range of customizable styles, layouts, and dynamic options for forms.
• Form Filling - Allow your end users to fill various of form data quickly, and effortlessly or directly from the internet or intranet.
• Form Flattening - Flatten AcroForm to make filled documents uneditable and searchable for archival or processing.
• Import/Export Form Data into/from PDF - Allow importing XFDF and FDF data into PDF forms, and also allow exporting your form data into XFDF and FDF formats.

Signatures

• Electronic Signature:
  • Drawn - Sign documents with a freehand drawing signature using a fingertip, stylus, or mouse.
  • Image - Sign documents with a photo of handwritten signatures.
  • Typed - Sign documents with a font-based signature which is created by typing and setting the font.
• Digital Signature:
  • Support creating P12 certifications, adding, or deleting the Digital Signatures.
  • Get the attribute set of certifications like certificate version, algorithm, issuer, etc.
  • Create Digital Signatures via CMS (Adbe.pkcs7.detached) method.
  • Support RSA signing algorithms.
  • Support SHA-2 (SHA-256) hashing algorithms.
  • Support OCSP, timestamp, and modification permission validation to verify document integrity, certificate trust, signature timestamp, etc.

Document Editor

• PDF Manipulation:
  • Split - Split PDF files by pages and save them in individual PDFs or split a particular collection of pages from a PDF file.
  • Extract Pages - Extract pages or page ranges from documents and save them as a new PDF document.
  • Merge - Combine and merge two documents or a list of documents into one PDF document.
• Page Edit:
  • Delete - Remove and get rid of one or more pages from a PDF.
  • Insert - Add a blank page/image, or select another PDF to insert into the existing document.
  • Crop - Define the cropping area and apply it to either a single page or all the pages to eliminate unnecessary information from the document.
  • Move - Move a single page or a group of pages, rearranging the pages within the PDF document.
  • Rotate - Rotate the chosen pages to 90, 180, and 270 degrees as you want.
  • Replace - Replace original document pages with new pages from a different document.
  • Exchange - Exchange and swap the location of two document pages.
  • Copy & Paste - Copy and paste PDF pages as you want to move them to a more proper position.
  • Reverse - Reverse the order of the pages of a PDF document.
• Document Information - Get or set the document information such as title, author, subject, and keywords to output PDF file.
• Extract Image - Extract the images from the selected pages or the whole PDF file, and save them to JPG files to be reused in other documents or programs.

Security

• Encryption - Secure your documents with passwords of different strengths - choose from AES-128, AES-256, or RC4 encryption methods.
• PDF Permission - Customizing the permission settings, allow or restrict users from performing specific actions such as content copying, printing, commenting, assembling the document, filling form fields, and more.
• Watermark - Create, insert, and remove text or image watermarks to brand your users' work and discourage its unauthorized use.
• Header & Footer - Create, edit, insert, and remove the header & footer to make the PDF documents more recognizable and professional.
• Bates Number - Create, edit, insert, and remove Bates numbers to index and find the specific page in a collection of documents.
• Background - Create, edit, insert, and remove background to change the default white background or add a background image.

Conversion

• PDF to PDF/A - Convert existing PDF files to PDF/A-compliant documents for long-term preservation, including PDF/A-1a and PDF/A-1b only.

Content Editor

• Edit Text:
  • Programmatically add and remove text in PDFs and make it possible to edit PDFs like Word. Allow selecting text to change the size, color, font, alignment, position, etc.
  • Undo or redo any change you made.
• Edit Image:
  • Support editing PDF images like adding, deleting, moving, rotating, cropping, replacing, scaling, mirroring, copying, and extracting.
  • Undo or redo any change you made.

Redaction

• Redact content including images, text, and vector graphics to remove sensitive information or private data, which cannot be restored once applied.
• Create redaction by selecting an area or searching for a specific text.
• Edit and save redaction annotations.

Compare Documents

• Content Comparison - Compare the text and image in the documents, showing all differences side by side.
• Overlay Comparison - Overlay two documents together for visual comparison, all changes could be viewed in one combined file.
• Changing List - All changes could be listed and navigated. Choosing the change types to display as you want.
• Compare Colors - Set the colors of stroke colors and blend mode for overlay comparison, and set the colors for different changes when choosing content comparison, making any differences between documents more obvious.

Optimization

• Compress - Reduce PDF document size with no or minimum visual quality loss.

Measurement

• Create and edit distance, perimeter, area, angle, diameter, radius, and volume measurement annotations.
• Change scale and precision of measurement annotations.