# Lettera extremely sluggish with large markdown file

**URL:** <https://community.bear.app/t/lettera-extremely-sluggish-with-large-markdown-file/19973>\
**Category:** Lettera\
**Tags:** bug\
**Created:** [October 12, 2026, 5:44pm UTC](https://community.bear.app/t/lettera-extremely-sluggish-with-large-markdown-file/19973 "2026-10-12T17:44:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![REZ2](https://avatars.discourse-cdn.com/v4/letter/r/76d3ee/32.png) [@REZ2](https://community.bear.app/u/REZ2)\
**Post date:** [October 12, 2026, 5:44pm UTC](https://community.bear.app/t/lettera-extremely-sluggish-with-large-markdown-file/19973/1 "2026-10-12T17:44:35Z")

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Now that Google supports downloads in markdown format from Google Docs…

I have downloaded some large docs, in markdown, and tried to edit them in Lettera.

Example: a 28M file with about 150K words. In Google Docs, no problem editing it.

Running Lettera 1.0.0 on an M3 Max MacBook Pro with 64GB

Problem: almost any edit takes 2-3 seconds with the spinning beach ball.

Even changing a header from J1 to H3. Everything is slow… to make any change.

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**Author:** ![tpw](https://avatars.discourse-cdn.com/v4/letter/t/eb9ed0/32.png) [@tpw](https://community.bear.app/u/tpw)\
**Post date:** [October 13, 2026, 12:32am UTC](https://community.bear.app/t/lettera-extremely-sluggish-with-large-markdown-file/19973/2 "2026-10-13T00:32:30Z")

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@REZ2 I’ve seen this happen when you have the same file open in either 2+ tabs or 2+ windows. I just checked with the latest beta version and _ **it’s still occurring in build 4458.** _

My MD file has 25k words so significantly smaller but I experience the same thing. Just double check if you have the file open in multiple places and if not you certainly have uncovered another bug.

-tom