diff --git a/services/web/scripts/history/HistoryUpgradeHelper.js b/services/web/scripts/history/HistoryUpgradeHelper.js
index 85cb1ba7d4..e3249ab8fa 100644
--- a/services/web/scripts/history/HistoryUpgradeHelper.js
+++ b/services/web/scripts/history/HistoryUpgradeHelper.js
@@ -1,9 +1,12 @@
 const { ReadPreference, ObjectId } = require('mongodb')
 const { db } = require('../../app/src/infrastructure/mongodb')
+const Settings = require('@overleaf/settings')
 
 const ProjectHistoryHandler = require('../../app/src/Features/Project/ProjectHistoryHandler')
 const HistoryManager = require('../../app/src/Features/History/HistoryManager')
 const ProjectHistoryController = require('../../modules/admin-panel/app/src/ProjectHistoryController')
+const ProjectEntityHandler = require('../../app/src/Features/Project/ProjectEntityHandler')
+const ProjectEntityUpdateHandler = require('../../app/src/Features/Project/ProjectEntityUpdateHandler')
 
 // Timestamp of when 'Enable history for SL in background' release
 const ID_WHEN_FULL_PROJECT_HISTORY_ENABLED = '5a8d8a370000000000000000'
@@ -292,8 +295,45 @@ async function anyDocHistoryIndexExists(project) {
   )
 }
 
+async function convertLargeDocsToFile(projectId, userId) {
+  const docs = await ProjectEntityHandler.promises.getAllDocs(projectId)
+  let convertedDocCount = 0
+  for (const doc of Object.values(docs)) {
+    const sizeBound = JSON.stringify(doc.lines)
+    if (docIsTooLarge(sizeBound, doc.lines, Settings.max_doc_length)) {
+      await ProjectEntityUpdateHandler.promises.convertDocToFile(
+        projectId,
+        doc._id,
+        userId
+      )
+      convertedDocCount++
+    }
+  }
+  return convertedDocCount
+}
+
+// check whether the total size of the document in characters exceeds the
+// maxDocLength.
+//
+// Copied from document-updater:
+// https://github.com/overleaf/internal/blob/74adfbebda5f3c2c37d9937f0db5c4106ecde492/services/document-updater/app/js/Limits.js#L18
+function docIsTooLarge(estimatedSize, lines, maxDocLength) {
+  if (estimatedSize <= maxDocLength) {
+    return false // definitely under the limit, no need to calculate the total size
+  }
+  // calculate the total size, bailing out early if the size limit is reached
+  let size = 0
+  for (const line of lines) {
+    size += line.length + 1 // include the newline
+    if (size > maxDocLength) return true
+  }
+  // since we didn't hit the limit in the loop, the document is within the allowed length
+  return false
+}
+
 module.exports = {
   determineProjectHistoryType,
   getUpgradeFunctionForType,
   upgradeProject,
+  convertLargeDocsToFile,
 }
diff --git a/services/web/scripts/history/upgrade_none_with_conversion_if_sl_history.js b/services/web/scripts/history/upgrade_none_with_conversion_if_sl_history.js
index 206bd5eb95..d62a114bb0 100644
--- a/services/web/scripts/history/upgrade_none_with_conversion_if_sl_history.js
+++ b/services/web/scripts/history/upgrade_none_with_conversion_if_sl_history.js
@@ -1,4 +1,4 @@
-const SCRIPT_VERSION = 3
+const SCRIPT_VERSION = 4
 const VERBOSE_LOGGING = process.env.VERBOSE_LOGGING === 'true'
 const WRITE_CONCURRENCY = parseInt(process.env.WRITE_CONCURRENCY, 10) || 10
 const BATCH_SIZE = parseInt(process.env.BATCH_SIZE, 10) || 100
@@ -16,11 +16,16 @@ process.env.MONGO_SOCKET_TIMEOUT =
 
 const PROJECT_ID = process.env.PROJECT_ID
 
+// User id is required to move large documents to filestore
+const USER_ID = process.env.PROJECT_ID
+const CONVERT_LARGE_DOCS_TO_FILE = process.env.DRY_RUN === 'true'
+
 const { ObjectId, ReadPreference } = require('mongodb')
 const { db, waitForDb } = require('../../app/src/infrastructure/mongodb')
 const { promiseMapWithLimit } = require('../../app/src/util/promises')
 const { batchedUpdate } = require('../helpers/batchedUpdate')
 const ProjectHistoryController = require('../../modules/admin-panel/app/src/ProjectHistoryController')
+const HistoryUpgradeHelper = require('./HistoryUpgradeHelper')
 
 console.log({
   DRY_RUN,
@@ -110,6 +115,13 @@ async function doUpgradeForNoneWithConversion(project) {
   const projectIdString = project._id.toString()
   if (!DRY_RUN) {
     try {
+      if (CONVERT_LARGE_DOCS_TO_FILE) {
+        const convertedDocCount =
+          await HistoryUpgradeHelper.convertLargeDocsToFile(projectId, USER_ID)
+        console.log(
+          `converted ${convertedDocCount} large docs to binary files for project ${projectId}`
+        )
+      }
       await ProjectHistoryController.migrateProjectHistory(projectIdString)
     } catch (err) {
       // if migrateProjectHistory fails, it cleans up by deleting