Supported formats: which files C-A-R-T-A opens
C-A-R-T-A opens the most common office files in your browser, with no software to install and no upload to a server. This page lists them all, with what you can do with each one and the limits.
The list
| Format | Extensions | What you can do |
|---|---|---|
| Every feature: reading, notes, graphic signature, OCR, pages, exports, AI. Password-protected PDFs too. | ||
| Digitally signed files | .p7m | Read the signed document and check the signatures. |
| Signatures and time stamps | .p7s, .tsd, .m7m | Open them and check signatures and time stamps. |
| E-invoices and XML | .xml | The invoice in readable form, or the XML with indentation. |
| Archives | .zip | The list of files inside; each one opens in a tab. |
| TIFF faxes and scans | .tif, .tiff | They become a PDF, multi-page too, with all the PDF features. |
| Images | .jpg, .jpeg, .png, .webp, .gif, .bmp | View, save, print and share them. |
| Text | .txt | Read, save, print and share it. |
The details of each format are on the features page.
.zip archives
An archive opens with no archive program: the list of files appears and each one opens in a new tab, with the features of its format. Password-protected files and suspicious ones (so-called "zip bombs", which swell enormously when unpacked) are flagged and not opened. Everything happens on your device. See open a ZIP file.
TIFF faxes and scans
TIFFs, even with many pages, become a PDF on your device: CCITT Group 3 and Group 4 faxes and TIFFs compressed with LZW, PackBits or JPEG open. From there OCR, signature, notes, printing and every other PDF feature work. TIFFs compressed with Adobe's "Deflate" method are not supported yet: C-A-R-T-A says so with a message. See open TIFF files and faxes.
Images
JPG, PNG, WebP, GIF and BMP photos and images open so you can look at them, save, print or share them. To read their text with OCR, annotate or sign them, for now you need a PDF: if the scan is a TIFF, C-A-R-T-A converts it by itself.
Several files at once
There is no need to open them one by one:
- From "Open". In the file picker choose more than one (with Ctrl or Shift on a computer, or with your phone's multiple selection).
- By dragging them. Drag several files onto the page at once.
- With "Open with…". With C-A-R-T-A installed as an app, select several files in your system and open them with C-A-R-T-A.
Each one opens in its own tab. Up to 8 files open at a time: if you choose more, C-A-R-T-A opens the first 8 and tells you. If you have turned tabs off in Settings, one file opens at a time.
To apply the same operation to a group of files (for example cleaning them up, compressing them or merging them into a single PDF) there is Several files at once instead, on the features page.
Your files stay on your device
Whatever the format, the file is read on your device. The text leaves it only when you use an AI feature or the "On the server" OCR yourself. Details on the privacy page.