# WebXDC: How Big is Too Big \[20MB\] **URL:** \ **Category:** Mini Apps\ **Tags:** solved, development, webxdc\ **Created:** [July 16, 2026, 4:28am UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545 "2026-07-16T04:28:11Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Axe](https://forum.delta.chat/user_avatar/forum.delta.chat/axe/32/1527_2.png) [@Axe](https://forum.delta.chat/u/Axe)\ **Post date:** [July 16, 2026, 4:28am UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/1 "2026-07-16T04:28:11Z")
What do you all think would be the largest useable size of a WebXDC app? I’m thinking about max size for sharing with Delta Chat users? The current app I’m working on is approaching 20MB. ---
**Author:** ![link2xt](https://forum.delta.chat/user_avatar/forum.delta.chat/link2xt/32/1971_2.png) [@link2xt](https://forum.delta.chat/u/link2xt)\ **Post date:** [July 16, 2026, 7:17am UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/2 "2026-07-16T07:17:45Z")
We had a limit of 640 kB in the past: [Proposal: remove/bump `.xdc` file size cap](https://support.delta.chat/t/proposal-remove-bump-xdc-file-size-cap/2828) On the sender the limit was removed: [feat: remove webxdc sending limit by link2xt · Pull Request #5268 · chatmail/core · GitHub](https://github.com/chatmail/core/pull/5268) Receivers had 4 MiB limit at some point which is also removed: [feat: remove receiver limit on .xdc size by link2xt · Pull Request #5058 · chatmail/core · GitHub](https://github.com/chatmail/core/pull/5058) Now there is no limit other than the limit on the message size enforced by email servers. 20 MB definitely sounds too big, with the whole Quake webxdc fitting in 5 MB. ---
**Author:** ![WofWca](https://forum.delta.chat/user_avatar/forum.delta.chat/wofwca/32/1702_2.png) [@WofWca](https://forum.delta.chat/u/WofWca)\ **Post date:** [July 16, 2026, 7:33am UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/3 "2026-07-16T07:33:22Z")
I don’t think there is a definitive answer (apart from, as @link2xt mentioned, how much the messenger and the server can itself handle). If you look at the size of videos, those often reach ~20MB in size, so I would say that 20 MB is fine. > [@link2xt](#): > > Quake webxdc fitting in 5 MB. That took some effort though: had to compromise on removing all player models except one and all maps except one. The original Quake demo assets (as opposed to the Open Arena ones that are budled with the .xdc file) would fit in around 20 MB if one were to compress them. ---
**Author:** ![ian](https://forum.delta.chat/user_avatar/forum.delta.chat/ian/32/3164_2.png) [@ian](https://forum.delta.chat/u/ian)\ **Post date:** [July 16, 2026, 8:55am UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/4 "2026-07-16T08:55:37Z")
This has already made rounds earlier: [q1k3.xdc](https://forum.delta.chat/uploads/short-url/49FLqfAve21lVacAgTM0YZJ1uC.xdc) (17.6 KB) > A tiny FPS for js13k. 2 levels, 5 types of enemies, 3 weapons, 30 different textures, music, dynamic lighting, doors, enemy AI with line of sight checks, spacial Audio Remember how even [100kB was enough](https://github.com/chatmail/core/commit/8ca54f616e8e6128ac86058cdec7a41cf18d8449) for webxdc in the beginning? ---
**Author:** ![Axe](https://forum.delta.chat/user_avatar/forum.delta.chat/axe/32/1527_2.png) [@Axe](https://forum.delta.chat/u/Axe)\ **Post date:** [July 16, 2026, 2:04pm UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/5 "2026-07-16T14:04:27Z")
I’m using ‘old school’ email server that I host myself on my own equipment, so file size is more or less unlimited. For the newer relays that people are setting up, are there file limit sizes built into those? (I don’t have a good understanding of relays, so hopefully this is not a dumb question.) ---
**Author:** ![link2xt](https://forum.delta.chat/user_avatar/forum.delta.chat/link2xt/32/1971_2.png) [@link2xt](https://forum.delta.chat/u/link2xt)\ **Post date:** [July 16, 2026, 2:11pm UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/6 "2026-07-16T14:11:58Z")
> [@Axe](#): > > I’m using ‘old school’ email server that I host myself on my own equipment, so file size is more or less unlimited. It is unlimited for you, but recipients on other servers may be unable to receive your webxdc if the message size is too large. Default restriction for chatmail relays is 30 MiB, and that is for base64-encoded message, so actual limit is roughly 20 MiB: > ---
**Author:** ![henk717](https://forum.delta.chat/user_avatar/forum.delta.chat/henk717/32/3687_2.png) [@henk717](https://forum.delta.chat/u/henk717)\ **Post date:** [September 7, 2026, 2:43pm UTC](https://forum.delta.chat/t/webxdc-how-big-is-too-big-20mb/5545/7 "2026-09-07T14:43:35Z")
It really depends on what the platform is you share them on and how you arrange the hosting. My Half-Life XDC works well on Armada for example, that one I can publish apps to with my own link so its just hosted on my own CDN whenever people use the option to add it to a chat. Bypasses the limit entirely. The biggest I went locally in building them was a bit over 500MB unpacked and then things really start to break with Vector running it fine and Armada breaking since it couldn’t handle the internal filesizes. The blossom servers usually have a file upload limit of 100mb so on that side thats about as big as you’d normally go without hosting it yourself / while preserving the shareability. For chatmail clients I assume it would be as high as the typical e-mail provider lets you go.