2026-09-26

SilverBullet: Upload Documents Larger Than 10 MiB

I recently stumbled over a slightly confusing limitation in SilverBullet: uploading larger documents worked using the Upload: File command, but dragging and dropping the very same file into the editor resulted in:

Document is too large, maximum is 10MiB

Turns out: this wasn't my configuration. It was a bug. 🤓

TLDR

To allow e.g. documents up to 100 MiB, add this to your SilverBullet CONFIG page:

config.set("maximumDocumentSize", 100)

And make sure you're running a SilverBullet version containing the fix from silverbulletmd/silverbullet#2159.

At the time of writing, that means using the edge Docker image.

The Problem

SilverBullet has a maximumDocumentSize configuration option.

For example:

config.set("maximumDocumentSize", 100)

The number is in MiB, so 100 means 100 MiB.

This is an important little detail. Do not use something like:

config.set("maximumDocumentSize", 100000000)

SilverBullet itself converts the configured value to bytes internally.

The confusing part was that the setting worked when using the Upload: File command, but not when pasting or dragging a document into the editor.

That behavior was reported in silverbulletmd/silverbullet#1621: the regular upload path read maximumDocumentSize from the configuration, while drag-and-drop and paste still used a hard-coded 10 MiB limit.

The Fix

PR silverbulletmd/silverbullet#2159 fixes exactly this.

Drag-and-drop and paste now query maximumDocumentSize from the SilverBullet configuration as well, falling back to the default limit when it isn't configured. The PR was merged on September 24, 2026.

There's one small catch.

The current stable release while I'm writing this is 2.11.1, released on September 22, 2026 — two days before the fix was merged.

So, temporarily, I'm running the edge image.

Docker Compose

My minimal setup looks roughly like this:

services:
  silverbullet:
    image: ghcr.io/silverbulletmd/silverbullet:edge
    restart: unless-stopped
    volumes:
      - ./data:/data
    ports:
      - "3000:3000"

SilverBullet officially provides both latest and edge: latest tracks stable releases, while edge tracks the current main branch.

After changing the image:

docker compose pull
docker compose up -d

Then open the CONFIG page in SilverBullet and add:

config.set("maximumDocumentSize", 100)

Reload SilverBullet and dragging a document larger than 10 MiB should now work.

Back to Stable

I wouldn't necessarily recommend staying on edge forever.

Once a stable release newer than 2.11.1 contains #2159, I'll simply change:

image: ghcr.io/silverbulletmd/silverbullet:edge

back to:

image: ghcr.io/silverbulletmd/silverbullet:latest

and update again.

One More Thing

maximumDocumentSize controls SilverBullet's limit.

If SilverBullet sits behind a reverse proxy, that proxy may have its own upload/body-size limit. So if the SilverBullet 10 MiB message disappears but you're suddenly greeted by an HTTP 413 Request Entity Too Large, that's a different layer you'll have to configure.

But for the mysterious:

Document is too large, maximum is 10MiB

despite having configured a higher maximumDocumentSize:

It wasn't you. It was that hard-coded 10. 😬