diff --git a/packages/ui/src/components/session-review.css b/packages/ui/src/components/session-review.css
index 30bfe3b712a9..35bee10484d7 100644
--- a/packages/ui/src/components/session-review.css
+++ b/packages/ui/src/components/session-review.css
@@ -170,6 +170,20 @@
     color: var(--icon-diff-modified-base);
   }
 
+  [data-slot="session-review-large-diff-badge"] {
+    font-family: var(--font-family-sans);
+    font-size: var(--font-size-small);
+    font-weight: var(--font-weight-medium);
+    color: var(--text-weak);
+  }
+
+  [data-slot="session-review-large-diff-warning"] {
+    font-family: var(--font-family-sans);
+    font-size: var(--font-size-small);
+    font-weight: var(--font-weight-medium);
+    color: var(--text-warning, var(--icon-diff-modified-base));
+  }
+
   [data-slot="session-review-file-container"] {
     padding: 0;
   }
diff --git a/packages/ui/src/components/session-review.tsx b/packages/ui/src/components/session-review.tsx
index fe2475548ea4..fe706633deb3 100644
--- a/packages/ui/src/components/session-review.tsx
+++ b/packages/ui/src/components/session-review.tsx
@@ -10,7 +10,7 @@ import { useDiffComponent } from "../context/diff"
 import { useI18n } from "../context/i18n"
 import { getDirectory, getFilename } from "@opencode-ai/util/path"
 import { checksum } from "@opencode-ai/util/encode"
-import { createEffect, createMemo, createSignal, For, Match, Show, Switch, type JSX } from "solid-js"
+import { createEffect, createMemo, createSignal, For, Match, onCleanup, Show, Switch, type JSX } from "solid-js"
 import { createStore } from "solid-js/store"
 import { type FileContent, type FileDiff } from "@opencode-ai/sdk/v2"
 import { PreloadMultiFileDiffResult } from "@pierre/diffs/ssr"
@@ -170,6 +170,16 @@ function markerTop(wrapper: HTMLElement, marker: HTMLElement) {
   return rect.top - wrapperRect.top + Math.max(0, (rect.height - 20) / 2)
 }
 
+const LARGE_DIFF_THRESHOLD = 500
+
+function diffLines(diff: FileDiff) {
+  return (diff.additions ?? 0) + (diff.deletions ?? 0)
+}
+
+function isLargeDiff(diff: FileDiff) {
+  return diffLines(diff) > LARGE_DIFF_THRESHOLD
+}
+
 export const SessionReview = (props: SessionReviewProps) => {
   let scroll: HTMLDivElement | undefined
   let focusToken = 0
@@ -177,25 +187,67 @@ export const SessionReview = (props: SessionReviewProps) => {
   const diffComponent = useDiffComponent()
   const anchors = new Map<string, HTMLElement>()
   const [store, setStore] = createStore({
-    open: props.diffs.length > 10 ? [] : props.diffs.map((d) => d.file),
+    open: props.diffs.length > 10 ? [] : props.diffs.filter((d) => !isLargeDiff(d)).map((d) => d.file),
   })
 
   const [selection, setSelection] = createSignal<SessionReviewSelection | null>(null)
   const [commenting, setCommenting] = createSignal<SessionReviewSelection | null>(null)
   const [opened, setOpened] = createSignal<SessionReviewFocus | null>(null)
+  const [confirmed, setConfirmed] = createSignal<Set<string>>(new Set())
+  let confirmTimer: ReturnType<typeof setTimeout> | undefined
+  onCleanup(() => {
+    clearTimeout(confirmTimer)
+    const current = open()
+    if (!current || current.length === 0) return
+    const large = largeDiffs()
+    if (large.size === 0) return
+    const filtered = current.filter((f) => !large.has(f))
+    if (filtered.length === current.length) return
+    props.onOpenChange?.(filtered)
+  })
 
   const open = () => props.open ?? store.open
   const diffStyle = () => props.diffStyle ?? (props.split ? "split" : "unified")
   const hasDiffs = () => props.diffs.length > 0
 
-  const handleChange = (open: string[]) => {
-    props.onOpenChange?.(open)
+  const largeDiffs = createMemo(() => {
+    const map = new Map<string, number>()
+    for (const d of props.diffs) {
+      if (isLargeDiff(d)) map.set(d.file, diffLines(d))
+    }
+    return map
+  })
+
+  const handleChange = (next: string[]) => {
+    const current = open() ?? []
+    const added = next.filter((f) => !current.includes(f))
+    const needsConfirm = added.filter((f) => largeDiffs().has(f) && !confirmed().has(f))
+
+    if (needsConfirm.length > 0) {
+      clearTimeout(confirmTimer)
+      setConfirmed((prev: Set<string>) => {
+        const s = new Set(prev)
+        for (const f of needsConfirm) s.add(f)
+        return s
+      })
+      confirmTimer = setTimeout(() => setConfirmed(new Set()), 3000)
+      const filtered = next.filter((f) => !needsConfirm.includes(f))
+      if (filtered.length !== current.length || filtered.some((f, i) => f !== current[i])) {
+        props.onOpenChange?.(filtered)
+        if (props.open !== undefined) return
+        setStore("open", filtered)
+      }
+      return
+    }
+
+    clearTimeout(confirmTimer)
+    props.onOpenChange?.(next)
     if (props.open !== undefined) return
-    setStore("open", open)
+    setStore("open", next)
   }
 
   const handleExpandOrCollapseAll = () => {
-    const next = open().length > 0 ? [] : props.diffs.map((d) => d.file)
+    const next = open().length > 0 ? [] : props.diffs.filter((d) => !isLargeDiff(d)).map((d) => d.file)
     handleChange(next)
   }
 
@@ -537,6 +589,20 @@ export const SessionReview = (props: SessionReviewProps) => {
                             </div>
                           </div>
                           <div data-slot="session-review-trigger-actions">
+                            <Show when={isLargeDiff(diff) && confirmed().has(diff.file) && !open().includes(diff.file)}>
+                              <span data-slot="session-review-large-diff-warning">
+                                {i18n.t("ui.sessionReview.largeDiff.clickToExpand", {
+                                  lines: String(diffLines(diff)),
+                                })}
+                              </span>
+                            </Show>
+                            <Show when={isLargeDiff(diff) && !confirmed().has(diff.file)}>
+                              <span data-slot="session-review-large-diff-badge">
+                                {i18n.t("ui.sessionReview.largeDiff.label", {
+                                  lines: String(diffLines(diff)),
+                                })}
+                              </span>
+                            </Show>
                             <Switch>
                               <Match when={isAdded()}>
                                 <span data-slot="session-review-change" data-type="added">
diff --git a/packages/ui/src/i18n/ar.ts b/packages/ui/src/i18n/ar.ts
index 7ee17e2e0102..d82d05685e12 100644
--- a/packages/ui/src/i18n/ar.ts
+++ b/packages/ui/src/i18n/ar.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "مضاف",
   "ui.sessionReview.change.removed": "محذوف",
   "ui.sessionReview.change.modified": "معدل",
+  "ui.sessionReview.largeDiff.label": "{{lines}} سطر",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} سطر — انقر مرة أخرى للتوسيع",
 
   "ui.lineComment.label.prefix": "تعليق على ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/br.ts b/packages/ui/src/i18n/br.ts
index 6d7449d8457d..494d7efbf823 100644
--- a/packages/ui/src/i18n/br.ts
+++ b/packages/ui/src/i18n/br.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Adicionado",
   "ui.sessionReview.change.removed": "Removido",
   "ui.sessionReview.change.modified": "Modificado",
+  "ui.sessionReview.largeDiff.label": "{{lines}} linhas",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} linhas — clique novamente para expandir",
 
   "ui.lineComment.label.prefix": "Comentar em ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/bs.ts b/packages/ui/src/i18n/bs.ts
index 24e4c12068ee..42aaca7f2dc0 100644
--- a/packages/ui/src/i18n/bs.ts
+++ b/packages/ui/src/i18n/bs.ts
@@ -12,6 +12,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Dodano",
   "ui.sessionReview.change.removed": "Uklonjeno",
   "ui.sessionReview.change.modified": "Izmijenjeno",
+  "ui.sessionReview.largeDiff.label": "{{lines}} linija",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} linija — kliknite ponovo za proširenje",
 
   "ui.lineComment.label.prefix": "Komentar na ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/da.ts b/packages/ui/src/i18n/da.ts
index 218f3b26a494..af78d69fd33c 100644
--- a/packages/ui/src/i18n/da.ts
+++ b/packages/ui/src/i18n/da.ts
@@ -9,6 +9,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Tilføjet",
   "ui.sessionReview.change.removed": "Fjernet",
   "ui.sessionReview.change.modified": "Ændret",
+  "ui.sessionReview.largeDiff.label": "{{lines}} linjer",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} linjer — klik igen for at udvide",
   "ui.lineComment.label.prefix": "Kommenter på ",
   "ui.lineComment.label.suffix": "",
   "ui.lineComment.editorLabel.prefix": "Kommenterer på ",
diff --git a/packages/ui/src/i18n/de.ts b/packages/ui/src/i18n/de.ts
index 921a12c99675..a6d1406d877d 100644
--- a/packages/ui/src/i18n/de.ts
+++ b/packages/ui/src/i18n/de.ts
@@ -13,6 +13,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Hinzugefügt",
   "ui.sessionReview.change.removed": "Entfernt",
   "ui.sessionReview.change.modified": "Geändert",
+  "ui.sessionReview.largeDiff.label": "{{lines}} Zeilen",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} Zeilen — erneut klicken zum Aufklappen",
   "ui.lineComment.label.prefix": "Kommentar zu ",
   "ui.lineComment.label.suffix": "",
   "ui.lineComment.editorLabel.prefix": "Kommentiere ",
diff --git a/packages/ui/src/i18n/en.ts b/packages/ui/src/i18n/en.ts
index 631bc660a65d..d8ba733befde 100644
--- a/packages/ui/src/i18n/en.ts
+++ b/packages/ui/src/i18n/en.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Added",
   "ui.sessionReview.change.removed": "Removed",
   "ui.sessionReview.change.modified": "Modified",
+  "ui.sessionReview.largeDiff.label": "{{lines}} lines",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} lines — click again to expand",
 
   "ui.lineComment.label.prefix": "Comment on ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/es.ts b/packages/ui/src/i18n/es.ts
index 4fd921b606b1..203b1fcece3e 100644
--- a/packages/ui/src/i18n/es.ts
+++ b/packages/ui/src/i18n/es.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Añadido",
   "ui.sessionReview.change.removed": "Eliminado",
   "ui.sessionReview.change.modified": "Modificado",
+  "ui.sessionReview.largeDiff.label": "{{lines}} líneas",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} líneas — clic de nuevo para expandir",
 
   "ui.lineComment.label.prefix": "Comentar en ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/fr.ts b/packages/ui/src/i18n/fr.ts
index 537d01bba941..44b70c9d339d 100644
--- a/packages/ui/src/i18n/fr.ts
+++ b/packages/ui/src/i18n/fr.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Ajouté",
   "ui.sessionReview.change.removed": "Supprimé",
   "ui.sessionReview.change.modified": "Modifié",
+  "ui.sessionReview.largeDiff.label": "{{lines}} lignes",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} lignes — cliquez à nouveau pour développer",
 
   "ui.lineComment.label.prefix": "Commenter sur ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/ja.ts b/packages/ui/src/i18n/ja.ts
index 6086070bdb2c..0f1d65e9e288 100644
--- a/packages/ui/src/i18n/ja.ts
+++ b/packages/ui/src/i18n/ja.ts
@@ -9,6 +9,8 @@ export const dict = {
   "ui.sessionReview.change.added": "追加",
   "ui.sessionReview.change.removed": "削除",
   "ui.sessionReview.change.modified": "変更",
+  "ui.sessionReview.largeDiff.label": "{{lines}} 行",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} 行 — もう一度クリックで展開",
   "ui.lineComment.label.prefix": "",
   "ui.lineComment.label.suffix": "へのコメント",
   "ui.lineComment.editorLabel.prefix": "",
diff --git a/packages/ui/src/i18n/ko.ts b/packages/ui/src/i18n/ko.ts
index fd394dbb7b52..6cd8935f130f 100644
--- a/packages/ui/src/i18n/ko.ts
+++ b/packages/ui/src/i18n/ko.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "추가됨",
   "ui.sessionReview.change.removed": "삭제됨",
   "ui.sessionReview.change.modified": "수정됨",
+  "ui.sessionReview.largeDiff.label": "{{lines}}줄",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}}줄 — 다시 클릭하여 펼치기",
 
   "ui.lineComment.label.prefix": "",
   "ui.lineComment.label.suffix": "에 댓글 달기",
diff --git a/packages/ui/src/i18n/no.ts b/packages/ui/src/i18n/no.ts
index dcb353614d30..68d87f5d3707 100644
--- a/packages/ui/src/i18n/no.ts
+++ b/packages/ui/src/i18n/no.ts
@@ -11,6 +11,8 @@ export const dict: Record<Keys, string> = {
   "ui.sessionReview.change.added": "Lagt til",
   "ui.sessionReview.change.removed": "Fjernet",
   "ui.sessionReview.change.modified": "Endret",
+  "ui.sessionReview.largeDiff.label": "{{lines}} linjer",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} linjer — klikk igjen for å utvide",
 
   "ui.lineComment.label.prefix": "Kommenter på ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/pl.ts b/packages/ui/src/i18n/pl.ts
index fb10debbb92d..3437b402289b 100644
--- a/packages/ui/src/i18n/pl.ts
+++ b/packages/ui/src/i18n/pl.ts
@@ -9,6 +9,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Dodano",
   "ui.sessionReview.change.removed": "Usunięto",
   "ui.sessionReview.change.modified": "Zmodyfikowano",
+  "ui.sessionReview.largeDiff.label": "{{lines}} linii",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} linii — kliknij ponownie, aby rozwinąć",
   "ui.lineComment.label.prefix": "Komentarz do ",
   "ui.lineComment.label.suffix": "",
   "ui.lineComment.editorLabel.prefix": "Komentowanie: ",
diff --git a/packages/ui/src/i18n/ru.ts b/packages/ui/src/i18n/ru.ts
index 417fe0ce8bfe..2dba51338ce9 100644
--- a/packages/ui/src/i18n/ru.ts
+++ b/packages/ui/src/i18n/ru.ts
@@ -9,6 +9,8 @@ export const dict = {
   "ui.sessionReview.change.added": "Добавлено",
   "ui.sessionReview.change.removed": "Удалено",
   "ui.sessionReview.change.modified": "Изменено",
+  "ui.sessionReview.largeDiff.label": "{{lines}} строк",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} строк — нажмите ещё раз для раскрытия",
   "ui.lineComment.label.prefix": "Комментарий к ",
   "ui.lineComment.label.suffix": "",
   "ui.lineComment.editorLabel.prefix": "Комментирование: ",
diff --git a/packages/ui/src/i18n/th.ts b/packages/ui/src/i18n/th.ts
index 68bb0d733d99..5b1f6d8395a0 100644
--- a/packages/ui/src/i18n/th.ts
+++ b/packages/ui/src/i18n/th.ts
@@ -8,6 +8,8 @@ export const dict = {
   "ui.sessionReview.change.added": "เพิ่ม",
   "ui.sessionReview.change.removed": "ลบ",
   "ui.sessionReview.change.modified": "แก้ไข",
+  "ui.sessionReview.largeDiff.label": "{{lines}} บรรทัด",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} บรรทัด — คลิกอีกครั้งเพื่อขยาย",
 
   "ui.lineComment.label.prefix": "แสดงความคิดเห็นบน ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/zh.ts b/packages/ui/src/i18n/zh.ts
index 53beeb1e4f0f..f5c91e2c12d2 100644
--- a/packages/ui/src/i18n/zh.ts
+++ b/packages/ui/src/i18n/zh.ts
@@ -12,6 +12,8 @@ export const dict = {
   "ui.sessionReview.change.added": "已添加",
   "ui.sessionReview.change.removed": "已移除",
   "ui.sessionReview.change.modified": "已修改",
+  "ui.sessionReview.largeDiff.label": "{{lines}} 行",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} 行 — 再次点击展开",
 
   "ui.lineComment.label.prefix": "评论 ",
   "ui.lineComment.label.suffix": "",
diff --git a/packages/ui/src/i18n/zht.ts b/packages/ui/src/i18n/zht.ts
index 1449b0530ac1..8aee1a22afca 100644
--- a/packages/ui/src/i18n/zht.ts
+++ b/packages/ui/src/i18n/zht.ts
@@ -12,6 +12,8 @@ export const dict = {
   "ui.sessionReview.change.added": "已新增",
   "ui.sessionReview.change.removed": "已移除",
   "ui.sessionReview.change.modified": "已修改",
+  "ui.sessionReview.largeDiff.label": "{{lines}} 行",
+  "ui.sessionReview.largeDiff.clickToExpand": "{{lines}} 行 — 再次點擊展開",
 
   "ui.lineComment.label.prefix": "評論 ",
   "ui.lineComment.label.suffix": "",