PDF, PDF/A, DOCX, PNG or JPG: which format should you use?

Start with what the reader needs to do

Formats are easiest to choose when you ask what happens after the file arrives.

• To be read exactly as laid out: If the reader should see the document exactly as you laid it out, and perhaps print or sign it, send a PDF.
• To keep working on it: If they need to keep working on it, send the editable format it was made in, like DOCX, XLSX or PPTX, or their OpenDocument equivalents.
• To post or annotate: If they need a picture to post, embed or annotate, send PNG or JPG.
• To last for years: If the document must stay readable for many years, archive it as PDF/A.
• To analyze numbers: If they need to analyze numbers, send CSV or a spreadsheet, not a PDF of a table.
• To read on phones: And if people will read it on phones or find it through search, an HTML page often serves better than any file.
• Always keep the source: In every case, keep the editable source as your master copy.

PDF: fixed layout that opens everywhere

• What PDF guarantees: A PDF records pages precisely: fonts are normally embedded, page size is exact, and the document looks the same in a browser, on a phone or on paper. That makes it the right format for final versions, anything that will be printed or signed, forms, invoices and documents where layout carries meaning.
• The same precision is its weakness. PDFs don't reflow, so small screens mean pinching and zooming, and editing is awkward because text is positioned instead of flowing.
• Getting content back out is lossy: PDF to Word can recover the words, but not a faithful copy of the original layout.
• Accessibility depends on how it was made: Accessibility also depends on how a PDF was made. A well-tagged PDF works with screen readers, while a scan without a text layer doesn't.

Word, Excel and PowerPoint: formats for working

Office formats are built for collaboration.

• Built for editing: A DOCX reflows to fit the reader's settings, keeps styles and track changes, and invites editing. An XLSX keeps live formulas, and a PPTX keeps animations and speaker notes.
• The risk in a final document: Those strengths create risks when a document is meant to be final. Layout can shift if the reader lacks your fonts, comments and tracked changes may reveal earlier drafts, and formulas can expose calculations you didn't intend to share.
• Send to edit, convert to read: Send office formats when you expect the recipient to edit, and convert to PDF when you want them to read. Word to PDF and Excel to PDF handle that step.
• OpenDocument alternatives: OpenDocument formats like ODT and ODS are open-standard alternatives that many public organizations prefer.

PDF/A: PDF built for the long term

• What the standard removes: PDF/A is an ISO standard that defines a restricted form of PDF for archiving. An ordinary PDF may rely on fonts installed on the reader's computer, device-dependent colors or features that future software might not support. PDF/A removes those dependencies: fonts must be embedded, colors must be defined against an embedded profile, and features like encryption and JavaScript aren't allowed.
• The parts of the standard: The standard has several parts. PDF/A-1 is the most restrictive, PDF/A-2 adds support for modern features like JPEG 2000 compression and transparency, and PDF/A-3 also allows other files to be embedded.
• What the tool produces: PDF to PDF/A produces PDF/A-2 files.
• Validate before you rely on it: When an archive or regulator requires compliance, check files with a validator like veraPDF, because not every input converts cleanly.

PNG and JPG: pictures of content

Image formats turn content into pixels.

• JPG for photographs: JPG uses lossy compression that suits photographs, producing small files by discarding detail the eye rarely misses, but it softens sharp edges. This makes text and line drawings look fuzzy.
• PNG for text and diagrams: PNG is lossless: every pixel is kept, so screenshots, diagrams, charts and text stay crisp, at the cost of larger files for photographs. PNG also supports transparency.
• One image, no searchable text: Both formats hold a single image, so a multi-page document becomes a set of files, and neither contains searchable text.
• When exporting pages makes sense: Exporting PDF pages as images makes sense for social posts, slides and image-only uploads; PDF to PNG suits text-heavy pages and PDF to JPG photo-heavy ones.
• WebP is a newer web format that's usually smaller still, but it's less widely supported outside browsers.

Every conversion has trade-offs

Converting between formats always loses something, and knowing what helps you convert in the right direction.

• What Word and PDF lose: Word to PDF can substitute fonts the converting system lacks. PDF to Word keeps text but not layout.
• Images and text layers: Images converted to PDF contain no searchable text until OCR is applied, and PDF pages converted to images lose their text layer entirely.
• Re-saving lossy formats: Lossy formats degrade a little every time they're re-saved, so converting a JPG to PDF and back to JPG repeatedly slowly blurs it.
• Two habits that avoid trouble: Two habits avoid most problems: keep the original source file, and convert once from that source to the format the recipient needs instead of chaining conversions through several formats.
• Where to read more: The guide to converting files to PDF covers what each converter keeps.

Size, compatibility and accessibility

A few rules of thumb help with practical constraints.

• Size: Text-based PDFs and office documents are small, while scanned PDFs and image exports are large, so a text PDF is usually the lightest way to send a long document. A PNG of a page of text is typically larger than a JPG of the same page but much sharper.
• Compatibility varies more than people expect: HEIC photos and WebP images still fail in some software, while PDF, JPG and PNG open almost everywhere.
• Accessibility: For accessibility, real text matters most. Screen readers handle HTML and well-tagged PDFs well, struggle with untagged PDFs, and can't read text inside images at all.
• Reading on phones: When a document will be read mainly on phones, publishing it as HTML with a PDF download gives readers the best of both.

Quick decisions for common situations

• A CV: For a CV, send a PDF unless the employer specifically asks for Word.
• A contract to sign: For a contract or agreement to be signed, send a PDF.
• A draft for colleagues: For a draft that colleagues will edit, share the DOCX or a shared document.
• An invoice: For an invoice, send a PDF and archive your copy as PDF/A if records must be kept for years.
• Figures to analyze: For figures someone needs to analyze, send CSV or XLSX instead of a table inside a PDF.
• Screenshots and photographs: For a bug report or tutorial, use PNG screenshots. For photographs, use JPG.
• A report on a website: For a report published on a website, publish HTML with a PDF version for download and printing.
• When unsure, ask the recipient what they need to do with the file. The answer usually settles the format.
• Where to read more: The guide to converting from PDF explains what can be recovered when you're handed the wrong format. When a document has to stay readable for years, the PDF/A archiving guide explains when that format is needed.

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