Lossless in, lossless out
TIFF and PNG are both lossless formats: neither throws away image detail to save space. Converting between them is therefore one of the few image conversions that costs nothing in quality — for an ordinary 8-bit image, every pixel of the PNG matches the TIFF exactly. What changes is where you can use the file. No major desktop browser can show a TIFF on a web page, many chat apps and upload forms reject it, and word processors handle it inconsistently. PNG works in all of them.
What to expect from the file size
| Your TIFF | The PNG will usually be |
|---|---|
| Uncompressed (common from scanners) | Much smaller |
| LZW or ZIP compressed | Roughly similar, often a little smaller |
| JPEG-compressed photo | Larger - PNG stores the photo without loss |
| Black-and-white document or fax | Small, with perfectly crisp text |
For detailed photographs where a small file matters more than perfect pixels, PNG is the wrong target — switch the output to JPG here, or use the TIFF to JPG converter, which is built around exactly that trade-off.
Transparency and 16-bit images
Logos, cut-out product shots and design assets are often saved as TIFFs with an alpha channel. PNG has a full alpha channel too, so transparent and partly transparent areas carry over unchanged — there is no background colour to choose and no dark fringe around the edges.
TIFFs with 16 bits per channel, common from film scanners and RAW processing, are converted to 8 bits per channel, which is what browsers work with. On screen the result is indistinguishable, and it is exactly what a web page or document needs. If you are going to push the colours hard in an editor, keep the 16-bit original alongside the PNG.
Scanned documents and faxes
Black-and-white document scans and faxes are usually stored as 1-bit TIFFs with
CCITT compression, often with several pages in one file. PNG suits them much better
than JPG: text edges stay perfectly sharp instead of picking up the faint smudges
JPG compression adds around letters. Each page comes out as its own PNG
(invoice-page-1.png, invoice-page-2.png…), all in
one ZIP, and small preview thumbnails that some scanners embed are skipped
automatically.
Which TIFFs work
Uncompressed, LZW, ZIP/Deflate, PackBits, JPEG-compressed and CCITT Group 3/4 files are supported, in RGB, CMYK, greyscale, palette and black-and-white. CMYK print files are converted to RGB with a standard formula, which can shift very saturated print colours slightly. If a TIFF uses a rare compression such as LZMA, you get an error naming the problem — never a blank image that looks like a successful result.
Private by design
The TIFF is read and saved as PNG entirely inside your browser. Nothing is uploaded, so scanned IDs, contracts and unreleased artwork stay on your device. There is no account, no watermark and no limit on the number of files.