Why convert images to PDF?
PDFs are the universal format for sharing documents. Unlike JPEG or PNG, a PDF preserves the exact layout, doesn't get compressed differently by every email client, and can combine multiple images into a single file. Common reasons to convert:
- Sending scanned documents — contracts, ID, certificates — to a bank, employer, or university
- Combining multiple product photos into a single shareable lookbook or catalog
- Sending a photo portfolio as one file rather than 20 separate images
- Archiving physical receipts or handwritten notes that you've photographed
- Creating a simple photo book or presentation to share with family
How to convert images to PDF — step by step
The fastest method that works on any device without software:
- Open ImgSlim.com in your browser and click the Image to PDF tab.
- Drop your images — or click to browse and select them. You can add multiple images at once. They'll be added to the PDF in the order you drop them.
- Set your options: Choose page size (A4, Letter, A3, or A5), orientation (portrait, landscape, or auto), margin size, and image quality.
- Name your file. Type a filename in the output field — for example, "passport-scan" or "product-photos".
- Click "Create PDF". The PDF is generated instantly in your browser and downloaded to your device. Nothing is uploaded anywhere.
If you're scanning documents for official purposes (visa applications, bank submissions), use High quality (95%) and A4 page size with small margins. This produces a clean, professional-looking PDF that meets most official requirements.
What image formats can be converted to PDF?
ImgSlim supports all common image formats as input for PDF conversion:
| Format | PDF supported | Notes |
|---|---|---|
| JPEG / JPG | ✓ Yes | Best for photos. Smallest resulting PDF. |
| PNG | ✓ Yes | Good for screenshots, graphics with transparency. |
| WebP | ✓ Yes | Converted automatically to JPEG inside the PDF. |
| GIF | ✓ Yes | Only the first frame is used (static). |
| BMP | ✓ Yes | Converted and optimized automatically. |
| HEIC (iPhone) | ✓ Most browsers | Works in Chrome and Safari; may not work in Firefox. |
PDF page size and orientation guide
Choosing the right page size depends on how the PDF will be used:
- A4 (210×297mm): Standard internationally. Use for any formal document, CV, or submission to a non-US organization.
- Letter (215.9×279.4mm): Standard in North America. Use for US forms, US university applications, US government submissions.
- A3 (297×420mm): Larger format, good for posters, portfolios, or technical drawings.
- A5 (148×210mm): Half of A4. Good for small booklets or compact documents.
- Auto orientation: ImgSlim detects whether each image is landscape or portrait and rotates the page accordingly — the best option when combining mixed photos.
How to combine multiple images into one PDF
The process is the same as a single image — just add multiple files at once. Each image becomes one page in the PDF. The order of pages matches the order you added the images.
Tip for ordering: Add images in the order you want them to appear. If you need to reorder, click "Clear all" and re-add them in the correct sequence.
Combining many images? There's no limit on the number of images. You could combine 50 photos into a 50-page PDF. However, for very large PDFs (100+ high-resolution photos), the process may take a few seconds as everything is calculated in your browser.
Alternative methods for converting images to PDF
On Windows
Open the image in Photos, click the print icon, and select "Microsoft Print to PDF" as the printer. This works for single images. For multiple images, you'd need to print them all and manually combine — ImgSlim's tool is faster.
On Mac
Open the image in Preview, then go to File → Export as PDF. To combine multiple images, open them all in Preview, select them all in the sidebar, then go to File → Print → Save as PDF.
On iPhone
In the Photos app, select multiple photos, tap the share icon, and choose "Print". Then pinch to zoom on the print preview — this creates a PDF you can save. ImgSlim's browser tool works too, directly in Safari.
On Android
Use ImgSlim in Chrome — the browser tool works the same on Android as on desktop. Or use Google Photos → select photos → Share → Print → Save as PDF.
Why your images should stay on your device
Most online image-to-PDF converters upload your files to their servers to process them. If you're converting sensitive documents — ID cards, passports, bank statements, medical records — this is a serious privacy risk. You don't know who can access those servers or how long your files are stored.
ImgSlim generates the PDF entirely in your browser using JavaScript. Your images are never sent anywhere. This makes it safe for sensitive documents.
Convert your images to PDF free
Drop your photos into ImgSlim. Combine multiple images into one PDF instantly — nothing uploaded, nothing stored.
Convert images to PDF →