Stirling PDF

editing PDF content with Stirling PDF, where the Content and editing documentation describes a PDF Text Editor that lets the user edit the existing text and images of a PDF, with a warning that the feature is in alpha and that fonts and layout can shift, plus adding images in PNG, JPEG, GIF, BMP, TIFF and SVG, extracting images, adding text, adding text or image stamps with position, size, rotation, opacity and dynamic variables, annotating with highlights, drawings, notes and shapes, removing images and annotations, and editing metadata and bookmarks; the scope records the existing-text editing with the alpha layout warning, and leaves OCR of scans to the OCR job, with no layout-stability guarantee

merging and splitting PDFs with Stirling PDF, where the Page operations documentation describes Merge joining two or more PDFs in the order shown with drag reordering or sort by file name or date, an optional table of contents with clickable bookmarks and an option to remove digital signatures that merging breaks anyway, and Split with page numbers, chapters, sections grid, file size, page count, document count, QR divider sheets and printable chunks methods, plus Reorganize Pages with custom order, reverse, duplex sort and odd-even modes, rotate and auto rotate; the scope records the documented merge, split and page operations and notes that merging breaks digital signatures

compressing PDFs with Stirling PDF, where the Compress documentation describes a Quality method with a Quality Adjustment slider from 1 to 9 defaulting to 5 where higher levels give smaller files but can blur images, a File Size method that takes a desired size in KB or MB, options for grayscale, linearization for fast web viewing and conversion of images to line art with a detail level from 1 to 5 and gentle, balanced or strong edge emphasis, and notes that the line-art option is unavailable where the tool cannot run it and that scans should be OCRed before compression; the scope makes no lossless or size-reduction guarantee

converting documents with Stirling PDF, where the Convert documentation lists conversion to PDF from Office formats DOCX, DOC, ODT, XLSX, XLS, ODS, PPTX, PPT, ODP, TXT and RTF, images JPG, JPEG, PNG, GIF, BMP, TIFF, WEBP and SVG, HTML and Markdown, email EML and MSG, eBooks EPUB, MOBI, AZW3 and FB2, and comics CBZ and CBR, with colour, fit, auto-rotate and combine options, and conversion from PDF to Office DOCX, ODT, PPTX, ODP, XLSX and CSV, text TXT, RTF and Markdown, images PNG, JPG, GIF, TIFF, BMP and WEBP at 72 to 600 DPI (default 300), HTML and XML, PDF/A, PDF/X and PDF/UA, and EPUB, AZW3, CBZ and CBR; Office and the listed route conversions normally need LibreOffice on a server or the cloud, and the scope makes no fidelity guarantee

signing PDFs with Stirling PDF, where the Sign documentation describes drawing, typing or uploading a visible signature (PNG, JPG or WebP with white backgrounds removed), scanning a QR code to sign on a phone, saving up to 20 signatures when signed in or 10 in the browser without signing in, and placing the signature repeatedly on any page and resizing it, while warning that the visible signature can be copied by anyone; the separate Certificate signing documentation describes signing with a PKCS12/PFX, PEM or JKS certificate from an upload, a server-held certificate or a device or USB token in the desktop app, with visible or invisible appearance, trust and revocation checks and RFC 3161 trusted timestamps set by the server administrator, and a validation tool that checks who signed and whether the file changed; the scope separates the visible electronic signature from the certificate signature and makes no certificate-authority or independent timestamping guarantee

running OCR with Stirling PDF, where the OCR documentation describes choosing every language that appears in the document (at least one is required), Auto, Force and Strict modes, and options for compatibility mode, a separate text file, deskewing, cleaning the input and cleaning the final output, with OCR my PDF used when installed and Tesseract otherwise; the OCR languages documentation says the tool can only offer languages whose Tesseract language pack is installed, that the standard Docker images include English, German, French, Portuguese and Simplified Chinese, that the ultra-lite image has no OCR, and that additional tessdata languages can be downloaded or mounted, while the desktop documentation says OCR usually needs Stirling Cloud or a server; the scope makes no accuracy or universal language-count claim

protecting PDFs with Stirling PDF, where the Signing and security tools documentation describes Add Password with a user password needed to open the file and an owner password controlling what can be done once open, Change Permissions to allow or block printing, copying, editing, form filling and other actions, Sanitize to remove JavaScript, embedded files, links, metadata and fonts, Flatten to merge form fields and interactive elements into the page, and Unlock PDF Forms, with separate tools to remove a password and to remove certificate signatures; the scope records the documented password, permission and sanitisation tools, leaves the black-box redaction tool to the redaction field, and makes no claim about which readers enforce the permission flags or about an encryption algorithm