Convert PNG to PDF Online
Turn PNG images into one-page PDFs sized to the image, so nothing is cropped or letterboxed onto A4. Bulk upload supported. Files are processed in memory and never stored.
Start ConvertingWhy Convert PNG to PDF?
Opens without an image viewer
Every operating system, browser and phone opens a PDF. Attaching one to an email or a form submission avoids the recipient needing anything at all.
The page matches the image
The PDF page is the image's own pixel dimensions at 72dpi, not a fixed A4 sheet. A wide screenshot stays wide instead of being shrunk into the middle of a portrait page.
Much smaller for photographs
A PNG photograph carries lossless data nobody can see. Measured on a 3840 x 2160 photo, the PDF came out 94% smaller than the PNG that went in.
Accepted where images are not
Upload portals for job applications, visas, invoices and court filings routinely accept PDF only. This is the conversion that gets a screenshot past that filter.
PNG vs PDF, measured
A PDF cannot hold a PNG. The image is re-encoded as JPEG at quality 90 and embedded, which is what every image-to-PDF tool does and what almost none of them tell you. That single fact decides whether your file gets dramatically smaller or noticeably bigger, and it depends entirely on what the picture is. Photographs win. Screenshots, logos and diagrams lose.
| Measure | PNG in | PDF out |
|---|---|---|
| Photograph, 3840 x 2160 | 21,691 KB | 1,310 KB |
| Size change, photograph | -- | 94% smaller |
| Flat colour screenshot | 49 KB | 154 KB |
| Size change, screenshot | -- | about 3x larger |
| Compression | Lossless | Lossy (JPEG q90) |
| Transparency | Yes | Flattened to white |
| Page size for the 4K image | -- | 53.3 x 30.0 in at 72dpi |
Reproduce with `node scripts/measure-pdf.mjs`, which runs the same src/lib/pdf.ts this converter uses. The photograph is a synthetic 3840 x 2160 gradient plus grain, the screenshot is flat colour with hard text edges; both are encoded from one decoded master so neither inherits the other's artifacts. The direction is what carries over, not the exact bytes. Rule of thumb: if your PNG is a photo, the PDF shrinks it hugely. If your PNG is a screenshot or a logo, expect the PDF to be several times larger, because PNG is already the better format for flat colour and JPEG is the worse one.
Frequently Asked Questions
Does my PNG stay lossless inside the PDF?
No. PDF embeds the picture as JPEG at quality 90, so this is a lossy step. For a photograph the difference is invisible and the file gets far smaller. For a screenshot with sharp text or a logo with hard edges you may see faint haloing, and the PDF will usually be larger than the PNG was. If you need the original pixels preserved exactly, keep the PNG.
What happens to transparency?
Transparent areas are filled with white. JPEG has no alpha channel, so the only alternative is encoding them as black, which looks obviously broken on logos and screenshots. White is the deliberate choice.
What size is the PDF page?
The page matches the image exactly, one pixel to one point. A 3840 x 2160 image gives a 53.3 by 30.0 inch page. It looks unusual in a page-size readout but it means the image is never cropped or letterboxed, and it prints scaled to fit whatever paper you use.
Can I put several PNGs into one PDF?
Not yet. Each image becomes its own single-page PDF. Upload a batch and you get a PDF per file, downloadable individually or as a ZIP. Merging them into one document is a different job than converting.
Does this count against the daily limit?
Yes. PNG to JPG or WebP runs in your browser and is unlimited, but PDF is the one target the browser cannot produce, so the file is uploaded and converted on the server. That counts toward the 20 files per day shared across converting and compressing.