If direct version-to-version online tools are unavailable, use an online converter to change the file into a universal format: How to SAVE 3DS MAX FILE in Lower Version (Step by Step)
Given the scarcity of true online converters, professionals generally rely on three specific workarounds that, while not purely "web-based," solve the problem efficiently: Convert 3ds Max File To Older Version Online
: Specifically supports conversion between different 3ds Max versions (e.g., converting a 2023 file to 2015). Note that this service may require payment or "points" for locally uploaded files. while not purely "web-based