Guides

Image formats, file sizes, PDFs, signatures and privacy, explained.

PNG vs JPG vs WebP: Which Image Format Should You Use?How PNG, JPG, WebP, SVG, and HEIC differ, with format guidance for photos, logos, screenshots, and websites.
How to Make an Image File Smaller Without Ruining ItHow dimensions and compression affect image file size, with practical settings for email, websites, and upload limits.
Why iPhone HEIC Photos Won't Open, and What to Do About ItWhat HEIC files are, why Windows and many websites reject them, how to convert HEIC to JPG or PNG, and how to stop your iPhone from creating them.
Transparent Backgrounds: How They Work and Which Formats Keep ThemHow alpha transparency works, why transparent images turn white or black when saved as JPG, and how to avoid halos and jagged edges in cutouts.
Image Sizes and Aspect Ratios for Social Media: A Practical GuideCommon social-media aspect ratios, safe areas for text, and a workflow for preparing one photo in several formats.
What Happens When You Merge PDFsWhat survives a PDF merge and what can break: bookmarks, links, form fields, page numbers, and file size, plus how to fix a merged document afterwards.
Typed, Drawn or Certificate: What Makes an Electronic Signature Count?The difference between typed signatures, signature images, and certificate-based digital signatures, with guidance on where each is used.
Why Is It So Hard to Edit a PDF?How PDF text is stored, why font subsetting affects edits, and workable methods for changing a PDF.
How to Turn Phone Photos into Clean, Small PDF ScansA practical workflow for scanning documents with a phone camera: shooting technique, cropping, contrast cleanup, converting to PDF, and combining pages.
How Local Browser Editing Handles Your FilesHow client-side file editing works, how to verify local processing, and what page data is still shared.