A designer finishes a logo or a poster and sends you the file they were working on: brand-final.psd or logo.ai. You do not own Photoshop or Illustrator, your computer shows a blank icon, and all you wanted was to see it, put it on a slide or send it to a printer.
What a PSD file holds
A PSD is Photoshop's working document. It keeps every layer separately, along with masks, adjustment layers, blend modes, layer effects and text that is still editable. That structure is what lets a designer go back and move one element without redrawing the rest.
Most PSD files also store one more thing: a flattened composite image, the finished picture with every visible layer combined. Photoshop writes it when the Maximize PSD and PSB File Compatibility preference is on, which it is by default, precisely so that other programs can show the file without understanding layers.
That composite is all a viewer needs. The PSD to PNG converter reads it in the browser and saves it as PNG, JPG or WebP. PNG keeps any transparent areas, which matters for logos placed on coloured backgrounds. Large .psb documents are accepted too.
What an AI file holds
Illustrator files work in a similar way. An .ai file saved with the default Create PDF Compatible File option contains a complete PDF of the artwork alongside Illustrator's own editing data. Every version since Illustrator 9 has done this.
So turning an AI file into a PDF is not really a conversion. The AI to PDF tool checks the file for that PDF and, if it is there, hands it over as a .pdf. Nothing is redrawn: vectors stay vectors and colours are exactly as saved. It can also render the artwork as PNG or JPG for slides and documents. Files saved without PDF compatibility, or by very old versions of Illustrator, are PostScript and cannot be read this way; the tool says so rather than producing an empty page.
What you lose, and why it rarely matters
Flattening a design into a PNG or PDF loses editability, not quality. You can no longer move a layer, change the text or swap a colour. For viewing, presenting and printing, that is irrelevant. For anything that will need changing later, keep the original file and treat the export as a copy.
Two details are worth checking in the result:
- Fonts. In a PSD the composite already shows text as pixels, so it looks right. In a PDF from an AI file, fonts are embedded if the designer saved them that way; if text looks substituted, ask for a PDF with fonts outlined.
- Resolution. A PSD composite is exactly the document's pixel size. A 1000-pixel-wide logo will look soft on a large poster, and no conversion can add detail that was never there.
Ask for the right format next time
The easiest fix is upstream. When you commission or receive design work, ask for the formats you will actually use:
| Use | Ask for |
|---|---|
| Printing | PDF, ideally with fonts embedded or outlined |
| Websites and apps | SVG for logos and icons, PNG or WebP for images |
| Slides and documents | PNG with a transparent background |
| Future edits | The original PSD or AI as well |
If all you have is a PNG of a logo and you need it to scale cleanly, a tracer such as PNG to SVG can rebuild it as vector shapes. It works well for flat logos with a few colours and poorly for anything photographic, so the original vector file from the designer is always the better answer when you can get it.