Contact Workbench
Move contact files with their names, labels and extra numbers intact. Inspect the data, decide what to merge, and keep an original-source archive alongside your new export.
How we build a check
This workbench processes supported inputs locally. We test calculations, file structure and generated artifacts using independent readers or known fixtures where available. The example runs the same processing path as a supplied input; it does not stand in for checking your own result.
Editorial responsibility
KitForma maintains this tool and its guides. The source notes on the tool page link to the supporting documentation. We do not claim affiliation with the referenced hardware manufacturers or platforms. Review date: 2026-10-18.
Limits and updates
Up to 20 vCard files, 8 MiB combined, 5,000 contacts, 100,000 total properties, 256 properties/contact and 1 MiB/embedded attachment. One UTF-8 CSV: 100 columns, 300,000 cells. Supported vCard 2.1 quoted-printable/declared character sets, UTF-8 vCard 3/4 and base64 media. Output archive up to 32 MiB. This is a bounded file reader/converter, not complete validation of every vCard extension or destination importer. If a specification changes or a result appears incorrect, send the relevant source URL and a non-sensitive reproduction to kitforma@outlook.com.
Open-source components
The tools use self-hosted open-source components appropriate to each format, including PDF.js, pdf-lib, fflate, SheetJS, MediaInfo by MediaArea.net SARL and others. Component versions and licenses. MediaInfo license · fflate license.