.ai — Adobe Illustrator Artwork
Image application/postscript
What a .ai file is
Illustrator's vector working format. Modern .ai files are actually PDFs with extra Illustrator data.
How to open it
Illustrator, or Inkscape and Affinity Designer with some loss of fidelity. Renaming to .pdf often opens it for viewing.
Worth knowing
For handing artwork to a developer, export SVG rather than sending the .ai.
How to identify a .ai file
A file's extension is only its name — renaming a.png to a.ai changes nothing inside. What software actually reads is the magic number, the first few bytes of the file.
| Signature | 25 50 44 46 |
| MIME type | application/postscript |
| Category | Image |
Modern .ai files are PDFs — the signature is "%PDF".
# what is this file really?
file mystery.ai
# look at the first bytes yourself
xxd mystery.ai | head -2
head -c 16 mystery.ai | xxd
# Windows PowerShell
Get-Content mystery.ai -AsByteStream -TotalCount 16 | Format-HexFrequently asked questions
What is a .ai file?
Illustrator's vector working format. Modern .ai files are actually PDFs with extra Illustrator data.
How do I open a .ai file?
Illustrator, or Inkscape and Affinity Designer with some loss of fidelity. Renaming to .pdf often opens it for viewing.
Is .ai safe to open?
Yes. A .ai file is data, not code — opening one cannot execute anything by itself.
Can I change a file's extension to convert it?
No. Renaming changes the label, not the bytes. The one place it appears to work is between formats that genuinely share a container — renaming .docx to .zip works because a DOCX is a ZIP. Everything else needs a real converter.
Other image formats
- .heic — High Efficiency Image Container
- .webp — WebP Image
- .avif — AV1 Image File Format
- .svg — Scalable Vector Graphics
- .psd — Photoshop Document
- .raw — Camera Raw Image