Images to PDF

Page size options — which one to choose

A4 (210×297mm) is the standard document size used in India, the UK, Europe, and most of the world. Use A4 when combining scanned documents, certificates, forms, or any content intended for official submission or printing. Most government portals, HR systems, and printers expect A4 as the default. Each image is scaled to fit within the A4 page with the margin you set, centred on the page.

Letter (216×279mm) is the US standard — slightly wider and shorter than A4. Use Letter if your content is intended for an American audience or an American printer. For most people outside the US, A4 is the right choice. The difference is subtle but matters if you're printing and want the content to fill the page properly without white borders.

A3 (297×420mm) is twice the size of A4 — useful for large diagrams, engineering drawings, or poster-format content. If your images are very wide or tall and you want them to print at full size on A3 paper, choose this. On standard A4/Letter printers, an A3 PDF will be scaled down automatically.

Fit to image creates a PDF where each page is exactly the pixel dimensions of the source image, converted to points. This is the right choice when you're archiving photos or artwork and want the PDF to be a faithful container for the original image dimensions — no scaling, no white space. The pages in the resulting PDF will each be a different size if your source images have different dimensions, which is fine for viewing but may look inconsistent when printed.

Image order is page order — get it right before converting

The image at the top of the list becomes page 1 of the PDF. Use the ↑↓ arrows to arrange images in exactly the order you want before clicking Convert. The most common mistake people make: uploading images in the wrong order, downloading the PDF, noticing it's wrong, then having to redo it. Take 10 seconds to check the order in the preview grid first.

If you're combining scanned pages of a multi-page document, number the scans before uploading (page-1.jpg, page-2.jpg, etc.) — they'll often load in alphabetical order which matches numerical order for single-digit pages, but breaks for 10+ pages (page-10 comes before page-2 alphabetically). Upload them manually in the right sequence if needed.

What images this tool accepts — and what it doesn't

The tool accepts JPEG, PNG, and WebP images. These are the three formats that browsers handle natively, which is why they work without any server-side conversion.

HEIC/HEIF — Apple's default photo format on iPhones (iOS 11 and later) — is not supported. Browsers don't have native HEIC decoding. To use iPhone photos here, convert them to JPG first: on iPhone, go to Settings → Camera → Formats → Most Compatible (this makes the camera shoot JPG instead of HEIC going forward). For existing HEIC files, share the photo and choose "Save as JPG" from the share sheet, or use a free HEIC-to-JPG converter online first.

TIFF, BMP, GIF, SVG are also not accepted. TIFF is common in professional scanning — convert to PNG or JPG before using here. BMP files are uncompressed and very large; convert to PNG. SVG is a vector format that this tool can't process — export your SVG as a PNG at the resolution you need first.

WebP is fully supported. This is Google's image format used widely on the web. If you've downloaded WebP images from a website and want to combine them into a PDF, they'll work here directly.

How the conversion works internally

The tool uses pdf-lib to create a new PDF document from scratch in your browser. For JPEG images, it embeds the JPEG data directly into the PDF — this is efficient because no re-encoding happens. For PNG and WebP images, it renders them to an HTML canvas element first (to normalise the format), then embeds the PNG data. Each image is scaled to fit within the page boundaries using the margin you set, maintaining the original aspect ratio so nothing gets stretched or squashed.

The images are embedded as-is — no compression is applied beyond what's already in the source file. A high-resolution JPEG stays high-resolution in the PDF. If you want a smaller output file, compress your source images before uploading, or use the PDF Compress tool after converting.

Common use cases

Scanned documents: The most common use. You've scanned a multi-page document on your phone using an app (CamScanner, Adobe Scan, Google PhotoScan) which saved each page as a separate JPG. Combine them here into one PDF to submit, share, or archive. Choose A4, normal margin, and arrange pages in order.

Photo albums for submission: Some portals or applications require a "photo portfolio" or "image gallery" as a single PDF. Combine your photos here with Fit to image and no margin for a clean, borderless presentation.

Creating a PDF from screenshots: If you've taken screenshots of something (a conversation, a website, software output) and need to submit them as a document, this is the fastest way to package them into one PDF. Use A4 with a small margin so the screenshots are framed cleanly on each page.

Certificate portfolios: Combining achievement certificates, completion badges, or qualification scans into one PDF for job applications or university submissions. Use A4, arrange in reverse chronological order (most recent first), and use a normal margin to keep everything readable.

Frequently asked questions

Will the image quality be reduced when converting to PDF?

No — for JPEG images, the original JPEG data is embedded directly without any re-compression. What you put in is what you get in the PDF. For PNG and WebP, the image goes through a canvas step for format normalisation, but the output is still a lossless PNG embedded in the PDF. The only quality reduction would come from scaling — if your image is larger than the page it's placed on, it gets scaled down to fit. Use "Fit to image" page size to avoid any scaling.

How many images can I combine at once?

There's no hard limit. Practically, your browser's available memory is the ceiling. 20–30 large images (several MB each) work fine on most devices. If you're combining 50+ high-resolution photos, the conversion may slow down significantly or fail on older phones. If you run into issues, split the job into two batches of 25, create two PDFs, then merge them using the PDF Merge tool.

Can I combine images and existing PDF pages in one document?

Not directly in this tool — it only accepts image files as input. If you need to combine image-based pages with existing PDF pages, the workflow is: convert your images to PDF here first, then use the PDF Merge tool to combine that PDF with your other PDFs in the right order.

The pages are in landscape but my images are portrait — what happens?

Each page takes the orientation you selected (A4 portrait by default). Your image is scaled to fit within the page, centred, with equal margins on all sides. A portrait image on a portrait A4 page fills most of the page with small margins. A landscape image on portrait A4 is fitted by width and will have large top/bottom white space. If you have landscape images, choose A4 Landscape — but currently the tool only offers portrait A4. For mixed-orientation documents, "Fit to image" is the cleanest option since each page matches its image's orientation exactly.

Is my data safe?

Yes — entirely. The tool runs inside your browser using pdf-lib, a JavaScript library that processes everything locally. Your images are loaded into browser memory, combined into a PDF there, and the resulting file is downloaded directly to your device. No image or PDF data is ever sent over the internet. You can use this with sensitive documents — medical records, ID scans, financial documents — without any concern about server-side storage.