Free online image to PDF converter. Upload photos or screenshots, reorder, choose size, compression, and export a multi-page PDF instantly. Works offline in your browser.
Convert Image to PDF Online Free
Upload one or more images, reorder, choose fit, and export a clean multi-page PDF.
Do not get lost! Hit Ctrl+D (Windows) or Command+D (Mac) to bookmark this tool for instant access.
How to Convert Images to PDF (Step by Step)
- Click Select Images and choose one or more images.
- Reorder using Up and Down in the preview cards.
- Pick page size, margins, and fit mode.
- Pick a compression level for smaller PDFs if needed.
- Click Export PDF. Save the file. Send it.
Supported Files & Privacy
You can add JPEG and PNG. Everything runs inside your browser. No file leaves your device. The code uses pdf-lib to create the PDF and a simple canvas pass for optional JPEG compression.
Feature Overview
- Multiple images in one PDF.
- Reorder before export with quick buttons.
- A4 or Letter in portrait or landscape.
- Margins in millimeters for printer-friendly pages.
- Fit to page, fill page, or keep original pixel size scaled by DPI.
- Optional JPEG compression for heavy photos.
- Memory guard with a clear warning for huge batches.
- All local. No upload. No watermark.
Fit Modes Explained
Fit to page scales the image to fit inside the printable area while keeping the aspect ratio. Nothing gets cropped.
Fill page scales the image to fill the printable area. It may crop the edges if the aspect ratio does not match the page.
Original size places the image using a DPI hint. Choose 96 for screen captures, 150 for decent print, 300 for high quality. If the image is large, it may extend past margins.
Choosing Page Size & Orientation
Pick A4 or Letter. Use portrait for tall documents and landscape for slides or wide diagrams. If you are scanning notes from a notebook, portrait A4 with 15 mm margins is safe for printing.
When to Use Compression (and Which Level to Pick)
Use “Original” for short documents or if you care about maximum quality.
Use “High” for most cases. You save size without visible loss.
Use “Medium” if you have a lot of photos.
Use “Small” for email limits or old phones that crash on big images.
Real-World Examples
Example 1: Scanned homework to a single PDF
- Input: 6 phone photos, each 12 MP.
- Settings: A4 Portrait, 15 mm margins, Fit to page, Compression High, DPI 150.
- Output: neat 6-page PDF, small enough for email, clear enough to print.
Example 2: Product screenshots to a slide-like PDF
- Input: 10 screenshots, various sizes.
- Settings: A4 Landscape, 10 mm margins, Fill page, Compression Original, DPI 96.
- Output: wide, clean pages. Edges cropped a bit for a full-frame look.
Example 3: Receipt archive for tax season
- Input: 40 receipt images.
- Settings: Letter Portrait, 12 mm margins, Fit to page, Compression Medium, DPI 150.
- Output: compact file that still shows numbers clearly.
Example 4: Poster artwork preview for a client
- Input: 3 PNG designs.
- Settings: A4 Portrait, 5 mm margins, Original size, DPI 300.
- Output: accurate sizing with small margins, good for printed proofing.
The Memory Problem Nobody Mentions
Very large images can hammer memory on old phones. The tool warns you if the total megapixels look risky. The practical fix is easy. Use Medium compression or split the batch into two PDFs. You keep the quality and avoid a crash.
Accuracy and Layout Tips
- Keep margins above 10 mm if you plan to print.
- Use Fit to page for clean edges and predictable results.
- Use Fill page for moodboards or when you want the full frame style.
- Use Original size when you must preserve exact physical size based on DPI.
- For logos and UI shots, PNG keeps edges sharp. For photos, JPEG is smaller.
How the Tool Works Under the Hood
The code uses pdf-lib to create pages in points. A4 and Letter are set in points. The margin input is converted from millimeters to points with the standard 1 point equals 1/72 inch. Images are embedded as JPEG or PNG. Optional compression uses a canvas pass to re-encode JPEG at a chosen quality setting before embedding. Positioning computes a content box from the page minus margins, then applies a scale based on your fit mode. Everything sits centered.
What About DPI
DPI is just a hint for mapping pixels to points. If you select 300 DPI, one pixel becomes 1/300 inch on the PDF. That makes an 1800 by 1200 image exactly 6 by 4 inches at print scale, before any fit scaling. If you use Fit to page, final size depends on the content box of the page. If you choose Original size, it uses DPI directly and may clip if the image is larger than the content box. Pick 150 for decent print or 300 for high fidelity.
Troubleshooting Checklist
- Export fails after long wait: choose Medium compression or fewer images.
- Pages look empty: the images may have alpha on white. Use Fill page or add a small margin.
- File looks huge: lower DPI from 300 to 150 and use High compression.
- Edges are cropped: change fit to Fit to page.
- Output is soft: switch compression to Original and DPI to 300.
Best Practices to Keep PDF Size Small and Sharp
- Shoot photos in good light. Noise packs bytes and looks fuzzy after compression.
- Crop dead space on the phone before export.
- Use High compression for photos and Original for logos or diagrams.
- Keep margins small but not zero for printer safety.
- Stick to one page size per document for consistency.
Common Questions
How can I convert images to PDF online for free without uploading them to a server?
This tool performs the conversion entirely in your browser using libraries like jsPDF or pdf-lib with canvas. Nothing is sent to a server, your images are processed locally for full privacy.
What image formats can I convert to PDF with an online tool?
Popular formats supported include JPG, PNG, GIF, BMP, TIFF, and even WEBP or SVG in some advanced converters.
Can I merge multiple images into one PDF file?
Yes. You can upload multiple images and order them as needed. The converter compiles them into a single multi-page PDF ideal for photo albums or portfolios.
Will the image quality be preserved when converting to PDF?
Absolutely. We retain image clarity and resolution, with no compression applied, ensuring your PDF stays sharp.
Do I need an account or to sign up to use online image-to-PDF tools?
Nope. Our tool is completely free and requires no signup or account, just upload and convert.
How do I convert an image to PDF on my mobile phone?
Open the converter in your phone’s browser, select a photo from your gallery or take a picture with your camera, and then export it as a PDF. It works on both Android and iPhone.
How fast is image to PDF conversion online?
The conversion usually takes just a few seconds per image. The speed depends on the size of your files and the performance of your device.
When You Should Use Multi-Page vs Single-Page PDF
Use multi-page when each photo is its own page of a story. Use single-page when you want a poster-like result. If you need a single long image inside one page, choose landscape and Fill page for a banner-like look but expect cropping.
Why This Is Better Than Desktop Apps for Quick Jobs
You get one minute from start to finish. No install. No updating. No subscription. Most desktop tools drown you in UI. This is simple. Upload. Order. Export. Done.
Print Quality in the Real World
At 150 DPI, standard printers produce clean classroom or office output. For photo-grade prints choose 300 DPI and Original compression. If you see banding or over-compressed blocks, switch to High or Original quality and re-export.
Accessibility and Mobile Support
The inputs are basic HTML elements that work with screen readers. Buttons are clearly labeled. The layout is responsive and tested on a narrow viewport. On very old phones, use fewer images or Medium compression.
Performance Profile
The biggest cost is decoding images and drawing them once to canvas when you enable compression. Pure PNG paths skip re-encode and embed directly. The PDF write step is fast compared to decode. For lots of images, keep the tab active and avoid switching apps during export.
File Naming and Organization Tips
Name files with a leading index before upload for a head start on order. You can always adjust with Up and Down. Keep a separate folder per project to avoid mixing receipts and screenshots. After export, rename the resulting PDF with date and topic.
Why Page Margins Matter
Many printers cannot print near the edge. A 10 to 15 mm margin keeps content safe. If you still need full bleed, choose Fill page and set margins to 0, then trim after printing.
Edge Cases You May Hit
- Huge panoramas in Original size may exceed the content area. Use Fit to page.
- Transparent PNGs on dark reader backgrounds can look odd in preview but export fine.
- Some PDF viewers throttle big files on slow devices. Open in a desktop reader if your phone viewer chokes.
Quick Cheatsheet
- Receipts: Fit to page, DPI 150, Medium compression.
- Homework: Fit to page, DPI 150, High compression.
- Mockups: Original size, DPI 300, Original compression.
- Screenshots: Fill page, DPI 96, Original compression.
Thank You Note
If you made it this far, you probably really needed this tool. I hope it saved you time and maybe even a bit of frustration. I keep building new tools every week, some small and some surprisingly powerful. You can check out all our free tools here and make sure to bookmark CodeForGeek so you never lose us.
If you have an idea for improvement or something is not working right, just email me at [email protected]. I actually read those messages, and if your suggestion makes sense, I will add it.
Thanks for sticking around till the end. Now go try out your result before you forget why you came here.
