How to Convert Images to PDF: A Complete Guide

Published August 25, 2026 · 7 min read

Whether you're submitting a set of scanned receipts for reimbursement, creating a photo portfolio, combining screenshots into a single document, or building a presentation from exported charts, converting images to PDF is a task that comes up constantly. This guide walks through every method — from simple one-click conversion to advanced batch processing with page sizing and margin control.

Why Convert Images to PDF?

Universal compatibility: PDF files open on any device without needing image viewer software.
Consistent formatting: A PDF preserves page order, sizing, and layout regardless of the viewer.
Single-file delivery: Instead of sending 20 separate JPGs, send one PDF. Email servers and users prefer this.
Printing: PDFs are the standard format for print shops and professional printing.
Archival: PDF/A (an ISO standard) ensures documents remain readable for decades.
Security: You can password-protect a PDF — try doing that with a folder of JPGs.

Supported Image Formats

Format	Extension	Notes
JPEG	.jpg, .jpeg	Most common. Lossy compression. Best for photographs.
PNG	.png	Lossless. Best for screenshots, text, charts with sharp edges.
WEBP	.webp	Modern format. Smaller files than JPEG at similar quality. Supported by Chrome, Firefox, Edge.
GIF	.gif	Supports animation but PDFs are static — only the first frame is used.
BMP	.bmp	Uncompressed. Very large files. Converts well to PDF.
TIFF	.tiff, .tif	Common in scanning and medical imaging. Supports multi-page.

Page Sizing Options

When converting images to PDF, you need to decide how images map to pages:

Fit (Original Size)

Each image is placed on a page sized to match the image's dimensions. A 1920×1080 image becomes a landscape page of the same aspect ratio. Best for: portfolios, photo collections, presentations.

A4 (210 × 297 mm)

Each image is scaled to fit within an A4 page. This is the standard paper size in most of the world. Best for: documents that will be printed on A4 paper, European and Asian submissions.

Letter (8.5 × 11 in)

Each image is scaled to fit within a US Letter page. Best for: US-based documents, academic submissions, business correspondence.

Legal (8.5 × 14 in)

Longer than Letter. Used for legal documents and contracts in the US.

Step-by-Step: How to Convert Images to PDF

Using our Images to PDF Tool (Browser-Based)

Select your images. Click the upload area or drag and drop multiple images at once. JPG, PNG, WEBP, and GIF are all supported.
Reorder if needed. Drag images to rearrange their order in the PDF.
Choose page size. Select A4, Letter, Fit (original size), or set custom dimensions.
Set margins. Choose between no margin, small (10mm), medium (20mm), or large (30mm) margins.
Generate the PDF. Processing happens entirely in your browser using jsPDF — no file uploads.
Download. Get your PDF instantly.

Using Command-Line Tools (Free)

# Using img2pdf (Python, produces small files — no re-encoding)
pip install img2pdf
img2pdf image1.jpg image2.png image3.jpg -o output.pdf

# Using ImageMagick
convert image1.jpg image2.png output.pdf

# Using Ghostscript
gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=output.pdf image1.jpg image2.png

⚠️ Image quality note: img2pdf copies image data directly into the PDF without re-encoding. This produces the smallest file and preserves exact image quality. ImageMagick and Ghostscript may re-encode images, which can slightly reduce quality or increase file size. For the best results, use img2pdf or a browser-based tool that doesn't re-encode.

Maintaining Image Quality in the PDF

A common concern: does converting an image to PDF reduce its quality? The answer depends on the tool:

Direct embedding (no re-encoding): Tools like img2pdf and our Images to PDF tool embed the original image data directly into the PDF. Quality is 100% preserved. File size increases slightly (PDF container overhead), but no image data is lost.
Re-encoding: Some tools decode the image and re-encode it as a different format inside the PDF. This can introduce quality loss (especially for JPEGs that are re-encoded at a lower quality setting) and increase file size.

Always verify the output by comparing a detail crop of the original image with the PDF version. If quality matters, choose a tool that performs direct embedding.

Batch Conversion Tips

When converting dozens or hundreds of images:

Name files in order. Use leading zeros: 001-cover.jpg, 002-intro.png. Most tools sort alphabetically.
Use consistent dimensions. If all images are the same resolution, the PDF pages will be uniform. Mixed resolutions create pages of varying sizes (which may look odd when printed).
Compress before converting. If your images are very large (e.g., 10 MP camera photos), resize them before converting to keep the PDF manageable. A 300 DPI scan of a letter-size page is about 2500×3300 pixels — that's more than enough for any PDF page.

Common Use Cases

Scanned receipts → PDF: Combine receipts into a single document for expense reports.
Phone photos → PDF: Convert photos of whiteboards, handwritten notes, or documents into shareable PDFs.
Screenshots → PDF: Combine multiple screenshots (e.g., of a website or app) into a single review document.
Design mockups → PDF: Package UI designs or artwork into a presentation-ready PDF.
Medical images → PDF: Combine X-ray or lab result images into a single document for your doctor.

Conclusion

Converting images to PDF is a simple operation, but getting the best results requires choosing the right page size, maintaining image quality, and using a tool that doesn't unnecessarily re-encode your images. For most users, a browser-based tool offers the best balance of convenience, quality, and privacy — your images never leave your device.

Convert your images to PDF — free, private, instant

Images to PDF Now

Related Guides

How to Compress a PDF — Reduce the size of your image-heavy PDFs after conversion.
PDF vs Scanned PDF — Understand the difference between image-based and text-based PDFs.
How to Merge PDF Files — Combine your converted PDFs with other documents.
PDF Security: How to Protect Your Documents — Protect image-heavy PDFs with passwords.