Success Story: INTEROFFICE – Collaborating on office documents without giving up privacy

by CryptPad team

The Challenge

Importing and exporting common office formats (Word, Excel, Powerpoint) is an expected feature for an online collaborative suite. However, all of the existing solutions perform these conversions by sending the document to their server and processing it there. This means the server can see the contents of the document.

As a result, anyone who wants to edit an office document with friends or colleagues currently has to choose between collaboration and privacy.

The Solution

With INTEROFFICE we have developed a document converter using Web Assembly. This is downloaded to the user’s browser so that document conversions can happen on their device rather than on the server. As with the rest of CryptPad, no un-encrypted data leaves the users’ browser and the server only facilitates collaboration without seeing any content.

We believe that collaboration doesn’t have to come at the price of privacy. CryptPad exists to demonstrate that it is possible to have both.

DAPSI journey – Achievements from first phase of the DAPSI programme

In phase 1 we completed most of the technical work on the converter that enables CryptPad to import and export MS Word, MS Powerpoint, and Open Document formats (in addition to MS Excel that was already implemented). We also added additional imports/exports following feedback from users: Trello boards can now be imported to CryptPad Kanban. Our Rich Text application can now export Markdown, and the import/export of Calendar is improved.

DAPSI journey – Achievements from second phase of the DAPSI programme

In phase 2 we introduced two new applications to make the most out of the new conversion capabilities: OnlyOffice Document and Presentation. We released them as early access to test them with our subscribers on and opt-in instance administrators. This new way of releasing new applications was part of broader conversations about future strategy with our DAPSI business coach.

We started integrating the new conversions in the CryptPad interface. Previously, office formats uploaded to CryptPad were treated as static files. They can now be converted into a CryptPad document and then be edited in the relevant application.

Preview of the new “Open in…” feature. Right clicking a compatible file in the drive shows this menu


We evaluated our work using data we gathered at the start of the project. We conducted a survey in the summer of 2021, between 15th July and 8th September. In line with INTEROFFICE project goals, our objective was to gather data about the needs of CryptPad users in terms of document conversions. We gathered 651 responses over the period. We used this data to evaluate the impact of our work on user workflows, to help elaborate our business strategy, and to identify potential areas of future work.

We counted that nearly 70% of pain points expressed by users at the start of the project have been addressed.

Thanks to this data we were able to draw up a map of how people move their documents between different formats. The map highlights that INTEROFFICE has allowed for significant improvement in the ways that CryptPad caters to the import/export needs of its users, especially when it comes to text documents (.docx or .odt). Comma Separated Values (.csv) remains an under-supported format to investigate in future work. This format poses significant challenges due to the fact that it supports multiple column separators despite its name. We also note that presentations (.pptx or .odp), while requiring the same amount of work as text documents, appear to solve less of a need. However, this map only reflects responses from existing users. It does not represent, for example, the number of new users that might now consider CryptPad as a tool to make presentations while they might not be users of our previous (and severely limited) “Markdown Slides” application.

Beyond CryptPad, we have also released our document converter as a standalone open-source repository. Other developers facing similar challenges will be able to benefit from our work and build on it for their own applications.

Open-source Office Converter
Online demo:
Source code:

Lessons learnt

As a small open-source team, we do not often have access to business advice from the startup world. The meetings with our DAPSI coach helped us face difficult questions about the sustainability of the project beyond research grants. We learned a lot about how to position ourselves, how to pitch our work, and how to build our customer base going forward.

We took all of this feedback on board and will be using it in the months ahead. For example, we are building a project website to differentiate CryptPad the open-source project from which is the flagship instance we administer. We will use this site to market our solution to showcase the project and how it can benefit different types of customers who we know already use it, for example education, NGOs, and enterprise.

 What’s next

The next few months will see even more exciting features being implemented in CryptPad. One thing that has been requested by enterprise users for a long time is integration with existing Single Sign On (SSO) solutions they may have in place. We are planning to implement this along with Multi-Factor Authentication this year.

More information

Flagship instance:

Social Media

Soure code on GitHub:
Donations on OpenCollective: