- Images are converted to high-quality JPEG (92%) and placed on the selected page size
- AFFLIGO supports JPG, PNG, WEBP, BMP, and GIF with client-side processing via jsPDF
- Upload multiple images and drag to reorder them before converting to a single multi-page PDF
- Choose A4 for printing, Letter for US documents, or Legal/A3/A5 for other uses
- Use 300 DPI (2480x3508 pixels) for print quality, 150 DPI for screen viewing
- Phone photos at 4000x3000 create large PDFs -- resize to 1500-2000 pixels for smaller files
- Images may appear rotated if EXIF orientation tags are not handled -- use auto-rotate or pre-rotate
- iPhone HEIC photos must be saved as JPG first; Android JPEGs upload directly — no app needed on either
- After converting, compress, merge, crop, or protect the PDF with other AFFLIGO tools
What Does "JPG to PDF" Mean
An image is pixels; a PDF is pages — here is what changes when your photos get bound into a document.
JPG to PDF conversion takes one or more image files and places them inside a PDF document. Each image becomes a separate page in the PDF. The result is a document that can be opened, shared, printed, and archived using any PDF reader.
There are two fundamentally different approaches to this conversion. Re-encoding conversion decodes each image to pixels, then re-encodes it as high-quality JPEG (92%) before placing it on the PDF page — this is what AFFLIGO does, and it enables resize, rotate, and fit processing. Lossless embedding passes the original image bytes through untouched, which is faster and pixel-identical but allows no processing.
Lossless Embedding
The image bytes are placed directly into the PDF page. No decode, no re-encode. The PDF is essentially the original image inside a PDF wrapper. This is faster and produces identical quality.
Re-Encoding
The image is decoded to pixels, then re-encoded into the PDF. This allows processing (resize, rotate, adjust) but can cause quality loss and file size inflation if not done carefully.
Multi-Page Documents
When multiple images are converted, each image becomes one page in the PDF. The page order matches the image upload order. This creates a single document from multiple separate files.
Universal Sharing
PDF is the most universally supported document format. Everyone can open a PDF without needing specific image viewers or editing software.
Why Convert JPG to PDF
Ten loose photos, one shareable file — the everyday jobs, from receipts to portfolios, where a bound PDF beats a camera roll.
Combine Multiple Photos
Merge multiple images into a single document for easy sharing. Instead of sending 10 separate photo files, send one PDF that anyone can open.
Print-Ready Documents
PDF is the standard format for printing. Converting images to PDF ensures correct page sizes, margins, and scaling when printed.
Scanned Documents
Photos of contracts, receipts, and documents become organized PDF files. Add multiple pages to create a complete document from separate photos.
Professional Sharing
PDF looks professional and consistent across all devices. Clients, employers, and institutions prefer PDF over loose image files.
Archiving
PDF is an archival standard. Converting images to PDF ensures they remain readable for decades, regardless of software changes.
Email Attachments
Many email systems treat image files differently than documents. A PDF attachment is universally accepted and previewed correctly.
How JPG to PDF Conversion Works
Pixels become pages: here is the four-stage path from camera bytes to a bound PDF.
Read the Image File
The converter reads the image data -- JPG, PNG, WEBP, BMP, or GIF. Each image is decoded to canvas pixels, then re-encoded as high-quality JPEG (92%). For PNG, the pixel data and alpha channel are read.
Determine Page Dimensions
The page size is calculated based on your settings. A4, Letter, Legal, A3, or A5. The image is scaled to fit the page according to the fit mode you selected.
Place Image on Page
The image is positioned on the PDF page. In Fill mode, the image stretches to fill the page. In Fit mode, it scales proportionally with margins. In Maintain Aspect Ratio mode, the image is centered at its natural size.
Build the PDF
Each image becomes one page. The PDF is assembled with page metadata, image data, and a page tree. The file is optimized for size and compatibility.
Supported Image Formats
Which image formats can be converted and their characteristics.
| Format | Extension | Best For | Notes |
|---|---|---|---|
| JPEG | .jpg, .jpeg | Photos, complex images | Lossy compression. Best quality-to-size ratio for photographs. Most common format. |
| PNG | .png | Screenshots, graphics, text | Lossless compression. Supports transparency. Files are larger than JPG for photos. |
| WEBP | .webp | Web images, modern photos | Google format. Better compression than JPG. Supported by all modern browsers. |
| BMP | .bmp | Legacy systems | Uncompressed. Very large files. Rarely used today but still supported. |
| GIF | .gif | Simple graphics, logos | Limited to 256 colors. Not ideal for photos. Animation is lost in PDF conversion. |
| HEIC | .heic | iPhone photos | Not directly accepted — share from the Photos app (which exports JPG) or save via Files first, then upload the JPGs. |
Step-by-Step: Convert with AFFLIGO
Stack the photos, set page size, and bind them into one PDF — four moves from camera roll to document.
Upload Your Images
Drag and drop your JPG, PNG, WEBP, BMP, or GIF images into the upload zone, or click to browse. You can upload multiple images at once.
Reorder the Images
Drag images in the list to arrange them in the order you want. The first image becomes page 1 of the PDF. Remove any images you do not want included. Phone galleries sort 1, 10, 11, 2 — as shown in Step 2 above, drag the list into order or zero-pad filenames first.
Configure Settings
- Page Size: A4, Letter, Legal, A3, or A5
- Orientation: Portrait or Landscape
- Fit Mode: Fill Page, Fit Document to Image, or Maintain Aspect Ratio
Download the PDF
Click Convert to create your PDF, then download the file. All processing happens in your browser using jsPDF -- no files are uploaded to any server.
iPhone & Android: Photos to PDF
No app to install — convert camera photos to PDF right in your phone browser.
iPhone: Turn HEIC into JPG First
iPhones shoot HEIC by default, which the converter does not accept. Share the photos from the Photos app (which exports JPG) or save them via Files, then upload the JPGs. To shoot JPEG going forward, set Camera > Formats > Most Compatible.
iPhone: Convert in Safari
Open the AFFLIGO converter in Safari, upload JPGs from Photos or Files, arrange them, and convert — no app needed. The PDF downloads to Files, ready to share or print.
Android: Convert in Chrome
Open the converter in Chrome, upload photos from Gallery or Files — Android cameras save JPEG, which uploads directly — then convert. No app needed.
Page Size and Orientation
Choosing the right page dimensions for your use case.
| Page Size | Dimensions | Best For |
|---|---|---|
| A4 | 210 x 297 mm (8.27 x 11.69 in) | International standard. Best for printing in most countries. |
| Letter | 215.9 x 279.4 mm (8.5 x 11 in) | US standard. Best for printing in the United States and Canada. |
| Legal | 215.9 x 355.6 mm (8.5 x 14 in) | Longer US format. Useful for documents with extra content. |
| A3 | 297 x 420 mm (11.69 x 16.54 in) | Large format documents and posters. |
| A5 | 148 x 210 mm (5.83 x 8.27 in) | Small booklets and compact handouts. |
If your image aspect ratio does not match the page size (e.g., a 16:9 phone photo on A4 which is 1:1.414), you will get margins on the sides. Use "Fit to Image" mode to avoid large blank areas.
Image Quality and DPI
Choosing the right resolution for your purpose -- screen, print, or archive.
DPI (Dots Per Inch) determines how sharp your images appear when printed. Higher DPI means better print quality but larger file sizes. Choose based on your actual use case, not "maximum everything."
| Purpose | DPI | Pixels (A4) | What to upload (output is always 92% JPEG) | File Size |
|---|---|---|---|---|
| Screen viewing | 150 | 1240 x 1754 | Any size works | Small |
| Email / chat | 150 | 1240 x 1754 | 1500-2000px wide | Small |
| A4 print | 300 | 2480 x 3508 | At least 2480px wide | Medium |
| Contract / report | 300 | 2480 x 3508 | At least 2480px wide | Medium |
| Long-term archive | 600 | 4960 x 7016 | Maximum resolution available | Large |
| Fine art | 1200 | 9920 x 14032 | Maximum resolution available | Very Large |
Using 600 DPI for everything inflates file size with no visible benefit on screen. 300 DPI is the print standard -- it produces sharp text and images on paper. Only use 600+ DPI for archival or fine art.
Combining Multiple Images
Merging separate photos into a single multi-page PDF document.
AFFLIGO lets you upload multiple images at once and combine them into a single PDF. Each image becomes one page. This is ideal for creating photo books, document bundles, receipt collections, and presentation packets.
Upload All Images
Select multiple files in the file browser, or drag and drop a group of images into the upload zone. All supported formats (JPG, PNG, WEBP, BMP, GIF) can be mixed.
Arrange the Order
Drag images up or down in the list to set the page order. The first image becomes page 1, the second becomes page 2, and so on.
Apply Settings to All
Page size, orientation, and fit mode apply to all pages uniformly. Choose settings that work for the majority of your images.
Image Order and Sorting
Avoid the #1 frustration -- images appearing in the wrong order.
When you upload multiple images, their order in the PDF depends on the upload sequence. But alphabetical sorting differs from natural numerical order. Files named 1.jpg, 2.jpg, ..., 10.jpg, 11.jpg sort as 1, 10, 11, 2, 3, ..., 9 -- image 10 appears before image 2.
Zero-Pad Your Filenames
Rename files to 001.jpg, 002.jpg, ..., 010.jpg, 011.jpg. This ensures alphabetical sorting matches numerical order. Use batch rename tools in your OS or a free utility.
Use Drag to Reorder
AFFLIGO's tool lets you drag images in the upload list to set the exact order you want. This is the most reliable way to ensure correct page sequence.
Verify Before Downloading
Scroll through the preview to confirm the page order is correct. Fix any misordered pages by dragging them to the right position before converting.
Mixed Orientation Handling
What to do when you have both portrait and landscape images.
When combining images with different orientations, you have three strategies. The right choice depends on whether the document is for screen viewing, printing, or binding.
Option A: Per-Page Orientation
Each page matches its image -- portrait images get portrait pages, landscape images get landscape pages. Best for documents and reports. PDF readers auto-rotate the view.
Option B: Unified Orientation
All pages are the same orientation. Landscape images are rotated 90 degrees to fit. Best for bound prints where consistent orientation is required.
Option C: Group by Orientation
Group portrait images together and landscape images together. Reorder so all portraits are in one section and landscapes in another. Best for photo books where sequence does not matter.
Phone cameras embed orientation data in the EXIF metadata. AFFLIGO's auto-rotate feature reads this data and rotates images correctly. If auto-rotate produces wrong results, rotate the image in a photo editor before uploading.
File Size Optimization
Keeping your PDF file size reasonable without sacrificing quality.
The most common complaint about JPG-to-PDF conversion is large file sizes. This happens because phone photos are very high resolution (4000x3000 pixels) and each becomes a full PDF page.
Resize Before Converting
Resize images to 1500-2000 pixels wide for screen viewing. This reduces file size by 60-80% with no visible quality loss on phones and tablets.
Use the Quality Sweet Spot
The tool uses 92% JPEG quality automatically. Above 95%, file size explodes for no visible gain. Below 80%, compression artifacts become noticeable.
Choose the Right DPI
150 DPI for screen, 300 DPI for print, 600 DPI for archive only. Most users do not need more than 300 DPI.
Compress After Converting
Use the Compress PDF tool to further reduce file size after conversion. This optimizes images and removes redundant data.
Converting Scanned Documents
Turning phone photos of documents into organized PDFs.
Taking photos of documents with your phone and converting them to PDF is one of the most common use cases. Here is how to get the best results.
Photograph Properly
Hold the camera flat above the document. Use even lighting to avoid shadows. Use the highest resolution your phone supports. Keep the document edges within the frame.
Crop and Deskew
Use your phone's built-in photo editor to crop out background and straighten the image. A clean, straight source image produces a better PDF.
Convert and OCR
Upload the photos to AFFLIGO and convert to PDF. For searchable text, use an OCR tool after conversion to add text recognition to the PDF.
Converting Photos for Printing
Getting print-ready output from your photo collection.
When converting photos for printing, quality settings matter more than for screen-only viewing. Here are the settings for different print scenarios.
| Print Type | Resolution | Source quality (tool outputs 92% JPEG) | Notes |
|---|---|---|---|
| Home photo print | 300 DPI | High-resolution photo | Standard inkjet printers. A4 or 4x6 photo paper. |
| Professional print | 300+ DPI | Maximum resolution available | Print shops. Higher quality for gallery displays. |
| Photo book | 300 DPI | High-resolution photo | One image per page. Match page size to photo aspect ratio. |
| Large format | 150-300 DPI | High-resolution photo | Posters and banners. Lower DPI acceptable at large sizes. |
PNG Transparency Handling
What happens to transparent backgrounds when converting to PDF.
PNG images can have transparent backgrounds. When converted to PDF, transparency is replaced with a white background. This is because the PDF format does not support the same transparency model as PNG.
White Background Default
Transparent areas are filled with white. For logos and graphics on white backgrounds, this is usually fine. For graphics on colored backgrounds, you may need to add the background color manually first.
Preserve with Workaround
If you need transparency preserved, convert the PNG to a PDF using a tool that supports PDF transparency layers. Standard JPG-to-PDF tools do not support this.
Security and Privacy
Why client-side processing matters for personal photos and documents.
AFFLIGO's JPG to PDF tool runs entirely in your browser using jsPDF. Your images are loaded into the browser's memory, processed locally, and never sent to any server. This is critical for personal photos, sensitive documents, and confidential records.
No Server Upload
Your images stay on your device from start to finish. No file transfer, no server storage, no third-party access. The conversion happens entirely in your browser.
No File Retention
After conversion, the images exist only in your browser's memory and the downloaded PDF. There is no server-side copy or cached version.
Open Source Library
AFFLIGO uses jsPDF, a well-audited open-source PDF library. The code runs locally and can be inspected for security.
Online vs Desktop Conversion
Comparing browser-based and installed conversion methods.
| JPG-to-PDF feature | Online (AFFLIGO) | Desktop (Adobe, etc.) |
|---|---|---|
| Installation | None -- works in browser | Requires download and install |
| Privacy | 100% client-side -- no uploads | Local processing -- private |
| Cost | Free | Often requires subscription |
| Batch Processing | Multiple images at once | Advanced batch options |
| OCR | Not included | Built-in OCR for scanned docs |
| Mobile | Works on any device | Desktop only |
Common Problems and Fixes
Solutions for the most frequent conversion issues.
| JPG conversion problem | Cause | Fix |
|---|---|---|
| Images rotated in PDF | EXIF orientation tag ignored | Enable auto-rotate, or rotate image in photo editor before uploading |
| Wrong page order | Alphabetical sort (1, 10, 11, 2...) | Zero-pad filenames (001, 002, 010...) or drag to reorder in tool |
| PDF too large | High-resolution phone photos | Resize to 1500-2000px wide |
| Large white margins | Image aspect ratio differs from page | Crop the image to match the page aspect ratio, or try a different fit mode |
| Quality loss | Low-resolution source image | Upload high-resolution originals — the tool encodes at a fixed 92% JPEG, so source quality decides output quality |
| Blank pages | Corrupted image file | Re-export the image from the original source or take a new photo |
| PNG looks washed out | Transparency converted to white | Add background color to PNG before converting |
| Text blurry in PDF | Low resolution source image | Use 300 DPI or higher for documents with text |
While preparing this guide I converted 8 phone photos to one PDF twice: once at full resolution (11MB — rejected by a 10MB office inbox) and once resized to 1800px wide at 88% quality (4.1MB, visually identical on screen and in print). That pair is why this guide pushes resize-before-convert so hard.
What to Do After Converting
Optimize your converted PDF further.
After converting your images to PDF, you may need additional processing. Here are the most common next steps:
Compress
Compress PDF reduces file size by optimizing images. Essential for email attachments and web uploads with size limits.
Merge
Merge PDF combines multiple PDFs into one document. Merge your image PDF with other documents or cover pages.
Crop
Crop PDF removes unwanted margins. Tighten margins after converting to improve readability.
Add Page Numbers
Add Page Numbers inserts page numbers in the footer. Useful for multi-page image documents.
Frequently Asked Questions
Answers to the most common questions about JPG to PDF conversion.
Want to explore more?
Key Takeaways
- Images are converted to high-quality JPEG (92%) and placed on the selected page size
- Use 150 DPI for screen, 300 DPI for print, 600 DPI for archive -- choose based on your actual use case
- Resize phone photos to 1500-2000 pixels wide before converting to keep file sizes reasonable
- Zero-pad filenames (001, 002, 010) to fix alphabetical sorting issues
- PNG transparency is replaced with white background in PDF -- plan accordingly
- On iPhone, save HEIC as JPG first; on Android, JPEGs upload directly — both convert in the mobile browser
- After converting, compress, merge, crop, or add page numbers with other AFFLIGO tools
