PNG to PDF Converter

Yes — this is a png to pdf converter free of charge: 100% free with no watermark, no account, and no upload. Your files never leave your browser, so there is nothing to pay for on a server — the conversion runs entirely on your own device.

No. This tool is 100% client-side: every step — PNG decoding, PDF writing, and the download — happens locally in your browser via JavaScript. You can even disconnect from the internet after the page loads and it will still work. No file ever touches nrtechstudio.com servers.

Not in Lossless mode (the default). The PNG pixels are decoded and embedded into the PDF bit-for-bit identical — zero quality loss, unlike tools that silently re-encode everything as JPEG. If you choose the JPEG mode instead, quality becomes lossy and is controlled by the quality slider.

In Lossless mode, transparency is preserved: the alpha channel is embedded as a PDF soft mask (/SMask), so transparent areas stay transparent in PDF readers that support it. In JPEG mode, transparency is flattened onto the background color you pick (white by default), because JPEG has no alpha channel.

There is no hard-coded limit — each image becomes one PDF page, in the order you arrange. In practice you are limited by your device's memory; dozens of photos work fine on a typical laptop or phone. Very large batches (hundreds of multi-megapixel images) may slow down older devices.

Yes. Drag and drop the thumbnails to rearrange them, or use the up/down arrow buttons on each thumbnail (handy on touch screens and keyboards). The preview list is exactly the page order of the final PDF.

A4, US Letter, and US Legal, each in portrait, landscape, or automatic orientation (auto matches the image: wide images get landscape, tall images get portrait). There is also a Fit mode where each page is sized exactly to its image at 150 DPI with no margins, plus margin presets of 0, 10, 20, or 30 mm.

This tool accepts PNG input and offers a true lossless embedding path designed for PNG (raw pixels via /FlateDecode with PNG predictors, alpha preserved as /SMask). The sibling jpg-to-pdf tool accepts JPEG input. Use this one whenever your source files are PNG — especially screenshots, diagrams, or images with transparency.

Two rare PNG variants are not supported and are rejected with a clear message instead of a corrupt PDF: interlaced (Adam7) PNGs and 16-bit-per-channel PNGs. Re-save the file as a standard non-interlaced 8-bit PNG in any image editor and it will convert fine.

Only the first frame. The converter reads the standard PNG image data (IDAT), which for an animated PNG corresponds to the default/first frame. Animation frames are not extracted — that is outside this tool's scope.

It is a rough estimate, not a promise. The estimate assumes typical deflate compression (about 55% of raw pixel size) plus per-page overhead. Simple graphics compress far better and noisy photos worse, so the real file can differ noticeably. The estimate exists to help you decide between Lossless and JPEG mode.

Yes. The tool writes standard PDF 1.4 with widely supported features: FlateDecode images with PNG predictors and soft masks are handled by Adobe Acrobat, Chrome/Edge, Firefox, Preview on macOS, and common mobile readers.

The PNG is decoded in pure JavaScript (signature and chunk parsing, zlib inflate, scanline unfiltering for all five PNG filter types). The original filtered pixel rows are then re-compressed and embedded as a PDF image XObject using /FlateDecode with /Predictor 15, which tells the reader to apply PNG unfiltering — so compression stays close to the original PNG size with zero pixel changes.

No. It runs in any modern browser (Chrome, Edge, Firefox, Safari) with JavaScript enabled — no install, no extension, no account, no email. On phones it works from the mobile browser the same way.