Image to PDF Converter — Convert JPG to PDF Free
PDF is the universal format for sharing documents. When you have a set of images — scanned receipts, signed contracts, photo documentation, or a series of charts — converting them into a single PDF makes them easier to send, archive, and print. An image to PDF converter handles this without requiring Adobe Acrobat or any desktop software. Keynou's converter runs in your browser, combines multiple images into one PDF, and gives you control over page size, orientation, and quality.
This guide covers how to combine images into a PDF, page size options, quality settings, and the practical scenarios where image-to-PDF conversion saves time.
Combining Multiple Images Into One PDF
The most common use case is merging a set of images into a single multi-page PDF. Each image becomes one page, in the order you specify. The image to PDF tool handles this in three steps:
- Upload images — drag and drop up to 50 images in JPG, PNG, WebP, or BMP format
- Arrange the order — drag images to reorder before converting
- Convert and download — the browser generates a single PDF file
The conversion happens entirely in the browser using the jsPDF library, which constructs the PDF document structure in memory and outputs it as a downloadable Blob. Your images never leave your device.
Page Size Options
Different use cases demand different page sizes. The converter supports three modes:
Standard Paper Sizes (A4, Letter, Legal)
The image is placed on a standard-sized page. If the image is smaller than the page, it's centered with whitespace margins. If it's larger, it's scaled down to fit within the page while maintaining aspect ratio.
| Page Size | Dimensions | Common Use |
|---|---|---|
| A4 | 210×297 mm (8.27×11.69 in) | International standard, most common |
| Letter | 8.5×11 in (216×279 mm) | US standard |
| Legal | 8.5×14 in (216×356 mm) | US legal documents |
A4 is the right default for most documents. Use Letter if the recipient is in the United States, where printers and filing systems are sized accordingly.
Fit to Image
Each page is sized exactly to match the image dimensions. There are no margins — the image fills the entire page. This is the best choice when:
- You want the PDF to display the image at its full original resolution
- The images have inconsistent dimensions and you don't want whitespace
- You're creating a digital portfolio where each page is a full-bleed photo
Custom Size
Enter specific width and height in millimeters or inches. Useful when you need a non-standard page size for a specific printer, label, or display.
Quality and Compression Settings
PDF files can embed images at different quality levels. Higher quality means larger files; lower quality means more compression artifacts.
Image quality (1–100): Controls the JPEG compression applied to images inside the PDF. At 90%, images look nearly identical to the originals. At 60%, file size drops significantly but photos show visible artifacts. For document scans, 75% is usually sufficient — text remains readable and file size stays manageable.
DPI (dots per inch): Controls the rendering resolution. Higher DPI produces sharper output on print but larger files. For screen viewing, 72 DPI is fine. For printing, use 150–300 DPI.
Practical Use Cases
Scanned Documents
If you've photographed or scanned multiple pages of a contract, receipt, or form, converting them to a single PDF is cleaner than sending a folder of images. Recipients can open one file, scroll through pages, and print the complete document. This is how most expense reports and insurance claims are submitted.
Photo Documentation
Real estate inspectors, contractors, and field technicians often capture dozens of photos on a job site. Combining them into a single PDF with page order matching the inspection sequence produces a professional deliverable that's easy to email and archive.
Design Portfolios
Designers compiling a portfolio can export each project as an image and merge them into one PDF. Using fit-to-image mode ensures each piece displays at full size without margins.
Educational Materials
Teachers who have worksheets, diagrams, and reference images as separate files can combine them into a single PDF for students. The page order creates a natural reading sequence.
Image to PDF vs PDF Merger
There's an important distinction between an image-to-PDF converter and a PDF merger:
- Image to PDF: Converts image files (JPG, PNG, WebP) into PDF pages, then combines those pages into one PDF
- PDF merger: Combines existing PDF files into a single PDF without converting formats
If your source files are images, use the image-to-PDF converter. If you already have PDFs that need combining, the PDF merger is the right tool. For workflows that involve both — converting images to PDF and then merging with existing PDFs — run the image conversion first, then merge all PDFs together.
Why Browser-Based Conversion Wins
Online image-to-PDF tools like iLovePDF and SmallPDF upload your images to their servers for processing. That's fine for casual use but problematic for:
- Confidential documents: Contracts, medical records, financial statements
- Speed: Uploading 20 high-resolution photos takes time
- Limits: Free tiers typically cap you at 20–30 images or a total file size
Keynou's converter processes everything locally. The jsPDF library runs in JavaScript within your browser, constructing the PDF byte-by-byte in memory. The only thing that leaves your device is the finished PDF you download.
For the technical specification of the PDF format, Adobe's PDF Reference is the authoritative source. The jsPDF GitHub repository documents the library that powers browser-based PDF generation.
Start Converting
Open the image to PDF converter, drop in your images, arrange the order, choose a page size, and download. No account, no upload, no watermark. If you also need to convert between image formats before creating your PDF, the image converter handles format switching in the same browser-based environment.
