diff --git a/components/app-header/load-srt.tsx b/components/app-header/load-srt.tsx
index ee50fe8..411ff31 100644
--- a/components/app-header/load-srt.tsx
+++ b/components/app-header/load-srt.tsx
@@ -12,6 +12,7 @@ import {
   AlertDialogTrigger,
 } from "@/components/ui/alert-dialog";
 import { Button } from "@/components/ui/button";
+import TranscriptImportDialog from "@/components/transcript-import-dialog";
 import {
   Dialog,
   DialogClose,
@@ -39,6 +40,7 @@ import { getReadableTextColor, getTrackHandleColor } from "@/lib/track-colors";
 import {
   IconBadgeCc,
   IconFile,
+  IconFileText,
   IconPencilPlus,
   IconPlus,
   IconTrash,
@@ -251,6 +253,16 @@ export default function LoadSrt() {
             );
           })}
 
+          <TranscriptImportDialog>
+            <Button
+              variant="secondary"
+              className="w-full cursor-pointer rounded-sm"
+            >
+              <IconFileText />
+              {t("buttons.importTranscript")}
+            </Button>
+          </TranscriptImportDialog>
+
           <Button
             variant="outline"
             onClick={() =>
diff --git a/components/subtitle/subtitle-list-empty.tsx b/components/subtitle/subtitle-list-empty.tsx
index 12731a7..319b0e0 100644
--- a/components/subtitle/subtitle-list-empty.tsx
+++ b/components/subtitle/subtitle-list-empty.tsx
@@ -1,6 +1,8 @@
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
+import TranscriptImportDialog from "@/components/transcript-import-dialog";
+import { IconFileText } from "@tabler/icons-react";
 import { useTranslations } from "next-intl";
 
 interface SubtitleListEmptyProps {
@@ -33,6 +35,16 @@ export default function SubtitleListEmpty({
       >
         {t("labels.startFromScratch")}
       </Button>
+      <p className="text-xl my-4">{t("labels.or")}</p>
+      <TranscriptImportDialog>
+        <Button
+          variant="link"
+          className="cursor-pointer text-xl text-muted-foreground underline hover:text-blue-800"
+        >
+          <IconFileText />
+          {t("labels.importTranscript")}
+        </Button>
+      </TranscriptImportDialog>
     </div>
   );
 }
diff --git a/components/subtitle/track-tabs.tsx b/components/subtitle/track-tabs.tsx
index e3284a3..580f73c 100644
--- a/components/subtitle/track-tabs.tsx
+++ b/components/subtitle/track-tabs.tsx
@@ -5,11 +5,13 @@ import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
+import TranscriptImportDialog from "@/components/transcript-import-dialog";
 import { getTrackColor, getTrackHandleColor } from "@/lib/track-colors";
 import type { SubtitleTrack } from "@/types/subtitle";
 import { useTranslations } from "next-intl";
 import { useTheme } from "next-themes";
 import type { Dispatch, RefObject, SetStateAction } from "react";
+import { IconFileText } from "@tabler/icons-react";
 
 interface TrackTabsProps {
   tracks: SubtitleTrack[];
@@ -76,6 +78,16 @@ export default function TrackTabs({
         >
           {t("labels.startFromScratch")}
         </Button>
+        <p className="text-xl my-4">{t("labels.or")}</p>
+        <TranscriptImportDialog>
+          <Button
+            variant="link"
+            className="cursor-pointer text-xl text-muted-foreground underline hover:text-blue-800"
+          >
+            <IconFileText />
+            {t("labels.importTranscript")}
+          </Button>
+        </TranscriptImportDialog>
       </div>
     );
   }
diff --git a/components/transcript-import-dialog.tsx b/components/transcript-import-dialog.tsx
new file mode 100644
index 0000000..e911326
--- /dev/null
+++ b/components/transcript-import-dialog.tsx
@@ -0,0 +1,375 @@
+"use client";
+
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogClose,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+  DialogTrigger,
+} from "@/components/ui/dialog";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { Textarea } from "@/components/ui/textarea";
+import {
+  useSubtitleActionsContext,
+  useSubtitleState,
+} from "@/context/subtitle-context";
+import {
+  segmentTranscriptToSubtitles,
+  TRANSCRIPT_SEGMENTATION_DEFAULTS,
+  type TranscriptSegmentationMode,
+  type TranscriptSegmentationOptions,
+} from "@/lib/transcript-segmentation";
+import { IconFileText, IconUpload } from "@tabler/icons-react";
+import { useTranslations } from "next-intl";
+import {
+  useId,
+  useMemo,
+  useState,
+  type ChangeEvent,
+  type ReactNode,
+} from "react";
+
+interface TranscriptImportDialogProps {
+  children: ReactNode;
+}
+
+const TRACK_LIMIT = 4;
+
+const parseNumberInput = (value: string, fallback: number): number => {
+  const parsed = Number.parseFloat(value);
+  return Number.isFinite(parsed) ? parsed : fallback;
+};
+
+const getTxtTrackName = (fileName: string, fallback: string): string => {
+  const trimmed = fileName.trim();
+  if (!trimmed) return fallback;
+  return trimmed.replace(/\.txt$/i, "") || fallback;
+};
+
+export default function TranscriptImportDialog({
+  children,
+}: TranscriptImportDialogProps) {
+  const t = useTranslations();
+  const [open, setOpen] = useState(false);
+  const [transcriptText, setTranscriptText] = useState("");
+  const [trackName, setTrackName] = useState("");
+  const [mode, setMode] = useState<TranscriptSegmentationMode>(
+    TRANSCRIPT_SEGMENTATION_DEFAULTS.mode,
+  );
+  const [startTimeSeconds, setStartTimeSeconds] = useState(
+    String(TRANSCRIPT_SEGMENTATION_DEFAULTS.startTimeSeconds),
+  );
+  const [cueDurationSeconds, setCueDurationSeconds] = useState(
+    String(TRANSCRIPT_SEGMENTATION_DEFAULTS.cueDurationSeconds),
+  );
+  const [gapSeconds, setGapSeconds] = useState(
+    String(TRANSCRIPT_SEGMENTATION_DEFAULTS.gapSeconds),
+  );
+  const [maxCharactersPerCue, setMaxCharactersPerCue] = useState(
+    String(TRANSCRIPT_SEGMENTATION_DEFAULTS.maxCharactersPerCue),
+  );
+  const fileInputId = useId();
+  const { loadSubtitlesIntoTrack, renameTrack, setInitialSubtitles } =
+    useSubtitleActionsContext();
+  const { tracks, activeTrackId } = useSubtitleState();
+
+  const defaultTrackName = t("transcriptImport.defaultTrackName");
+  const effectiveTrackName = trackName.trim() || defaultTrackName;
+  const activeTrack = activeTrackId
+    ? tracks.find((track) => track.id === activeTrackId)
+    : null;
+  const activeTrackIsEmpty = Boolean(
+    activeTrack && activeTrack.subtitles.length === 0,
+  );
+  const cannotCreateTrack = tracks.length >= TRACK_LIMIT && !activeTrackIsEmpty;
+  const destinationText =
+    activeTrack && activeTrackIsEmpty
+      ? t("transcriptImport.destinationReplace", { track: activeTrack.name })
+      : t("transcriptImport.destinationNewTrack");
+
+  const segmentationOptions = useMemo<TranscriptSegmentationOptions>(
+    () => ({
+      mode,
+      startTimeSeconds: parseNumberInput(
+        startTimeSeconds,
+        TRANSCRIPT_SEGMENTATION_DEFAULTS.startTimeSeconds,
+      ),
+      cueDurationSeconds: parseNumberInput(
+        cueDurationSeconds,
+        TRANSCRIPT_SEGMENTATION_DEFAULTS.cueDurationSeconds,
+      ),
+      gapSeconds: parseNumberInput(
+        gapSeconds,
+        TRANSCRIPT_SEGMENTATION_DEFAULTS.gapSeconds,
+      ),
+      maxCharactersPerCue: parseNumberInput(
+        maxCharactersPerCue,
+        TRANSCRIPT_SEGMENTATION_DEFAULTS.maxCharactersPerCue,
+      ),
+    }),
+    [
+      mode,
+      startTimeSeconds,
+      cueDurationSeconds,
+      gapSeconds,
+      maxCharactersPerCue,
+    ],
+  );
+
+  const previewSubtitles = useMemo(
+    () => segmentTranscriptToSubtitles(transcriptText, segmentationOptions),
+    [transcriptText, segmentationOptions],
+  );
+
+  const importDisabled = cannotCreateTrack || previewSubtitles.length === 0;
+
+  const handleFileSelect = async (event: ChangeEvent<HTMLInputElement>) => {
+    const file = event.target.files?.[0];
+    if (!file) return;
+
+    const text = await file.text();
+    setTranscriptText(text);
+    setTrackName(getTxtTrackName(file.name, defaultTrackName));
+    event.currentTarget.value = "";
+  };
+
+  const handleImport = () => {
+    if (importDisabled) return;
+
+    if (activeTrackId && activeTrackIsEmpty) {
+      loadSubtitlesIntoTrack(activeTrackId, previewSubtitles);
+      renameTrack(activeTrackId, effectiveTrackName);
+    } else {
+      setInitialSubtitles(previewSubtitles, effectiveTrackName);
+    }
+
+    setOpen(false);
+  };
+
+  return (
+    <Dialog open={open} onOpenChange={setOpen}>
+      <DialogTrigger asChild>{children}</DialogTrigger>
+      <DialogContent className="sm:max-w-5xl max-h-[90vh] overflow-y-auto">
+        <DialogHeader>
+          <DialogTitle>{t("transcriptImport.title")}</DialogTitle>
+          <DialogDescription>
+            {t("transcriptImport.description")}
+          </DialogDescription>
+        </DialogHeader>
+
+        <div className="grid gap-4">
+          <div className="grid gap-2">
+            <Label htmlFor={fileInputId}>
+              {t("transcriptImport.fileLabel")}
+            </Label>
+            <div className="flex items-center gap-2">
+              <Button asChild variant="outline">
+                <Label htmlFor={fileInputId} className="cursor-pointer">
+                  <IconUpload />
+                  {t("transcriptImport.chooseFile")}
+                </Label>
+              </Button>
+              <Input
+                id={fileInputId}
+                type="file"
+                className="hidden"
+                accept=".txt,text/plain"
+                onChange={handleFileSelect}
+              />
+              <span className="text-sm text-muted-foreground">
+                {t("transcriptImport.fileHint")}
+              </span>
+            </div>
+          </div>
+
+          <div className="grid gap-2">
+            <Label htmlFor="transcript-import-text">
+              {t("transcriptImport.pasteLabel")}
+            </Label>
+            <Textarea
+              id="transcript-import-text"
+              value={transcriptText}
+              onChange={(event) => setTranscriptText(event.target.value)}
+              placeholder={t("transcriptImport.pastePlaceholder")}
+              className="min-h-36 resize-y text-sm md:text-sm"
+            />
+          </div>
+
+          <div className="grid gap-3 md:grid-cols-5">
+            <div className="grid gap-1 md:col-span-2">
+              <Label htmlFor="transcript-import-track-name">
+                {t("transcriptImport.trackNameLabel")}
+              </Label>
+              <Input
+                id="transcript-import-track-name"
+                value={trackName}
+                onChange={(event) => setTrackName(event.target.value)}
+                placeholder={defaultTrackName}
+                className="px-2 py-2"
+              />
+            </div>
+            <div className="grid gap-1">
+              <Label htmlFor="transcript-import-mode">
+                {t("transcriptImport.modeLabel")}
+              </Label>
+              <select
+                id="transcript-import-mode"
+                value={mode}
+                onChange={(event) =>
+                  setMode(event.target.value as TranscriptSegmentationMode)
+                }
+                className="h-10 rounded-md border border-input bg-background px-2 text-sm shadow-xs focus-visible:outline-hidden focus-visible:ring-1 focus-visible:ring-ring"
+              >
+                <option value="lines">{t("transcriptImport.modeLines")}</option>
+                <option value="sentences">
+                  {t("transcriptImport.modeSentences")}
+                </option>
+                <option value="maxCharacters">
+                  {t("transcriptImport.modeMaxCharacters")}
+                </option>
+              </select>
+            </div>
+            <div className="grid gap-1">
+              <Label htmlFor="transcript-import-duration">
+                {t("transcriptImport.durationLabel")}
+              </Label>
+              <Input
+                id="transcript-import-duration"
+                type="number"
+                min="0.1"
+                step="0.1"
+                value={cueDurationSeconds}
+                onChange={(event) => setCueDurationSeconds(event.target.value)}
+                className="px-2 py-2"
+              />
+            </div>
+            <div className="grid gap-1">
+              <Label htmlFor="transcript-import-gap">
+                {t("transcriptImport.gapLabel")}
+              </Label>
+              <Input
+                id="transcript-import-gap"
+                type="number"
+                min="0"
+                step="0.1"
+                value={gapSeconds}
+                onChange={(event) => setGapSeconds(event.target.value)}
+                className="px-2 py-2"
+              />
+            </div>
+          </div>
+
+          <div className="grid gap-3 md:grid-cols-5">
+            <div className="grid gap-1">
+              <Label htmlFor="transcript-import-start">
+                {t("transcriptImport.startOffsetLabel")}
+              </Label>
+              <Input
+                id="transcript-import-start"
+                type="number"
+                min="0"
+                step="0.1"
+                value={startTimeSeconds}
+                onChange={(event) => setStartTimeSeconds(event.target.value)}
+                className="px-2 py-2"
+              />
+            </div>
+            <div className="grid gap-1">
+              <Label htmlFor="transcript-import-max-chars">
+                {t("transcriptImport.maxCharactersLabel")}
+              </Label>
+              <Input
+                id="transcript-import-max-chars"
+                type="number"
+                min="1"
+                step="1"
+                disabled={mode !== "maxCharacters"}
+                value={maxCharactersPerCue}
+                onChange={(event) => setMaxCharactersPerCue(event.target.value)}
+                className="px-2 py-2"
+              />
+            </div>
+            <div className="flex items-end md:col-span-3">
+              <p className="text-sm text-muted-foreground">
+                {cannotCreateTrack
+                  ? t("transcriptImport.trackLimitReached")
+                  : destinationText}
+              </p>
+            </div>
+          </div>
+
+          <div className="grid gap-2">
+            <div className="flex items-center justify-between">
+              <h3 className="text-sm font-semibold">
+                {t("transcriptImport.previewTitle")}
+              </h3>
+              <span className="text-sm text-muted-foreground">
+                {t("transcriptImport.cueCount", {
+                  count: previewSubtitles.length,
+                })}
+              </span>
+            </div>
+            <div className="max-h-60 overflow-auto rounded-sm border">
+              {previewSubtitles.length > 0 ? (
+                <table className="w-full text-left text-sm">
+                  <thead className="sticky top-0 bg-background">
+                    <tr className="border-b">
+                      <th className="w-16 px-2 py-2 font-medium">
+                        {t("transcriptImport.table.id")}
+                      </th>
+                      <th className="w-32 px-2 py-2 font-medium">
+                        {t("transcriptImport.table.start")}
+                      </th>
+                      <th className="w-32 px-2 py-2 font-medium">
+                        {t("transcriptImport.table.end")}
+                      </th>
+                      <th className="px-2 py-2 font-medium">
+                        {t("transcriptImport.table.text")}
+                      </th>
+                    </tr>
+                  </thead>
+                  <tbody>
+                    {previewSubtitles.map((subtitle) => (
+                      <tr
+                        key={subtitle.uuid}
+                        className="border-b last:border-0"
+                      >
+                        <td className="px-2 py-2 align-top">{subtitle.id}</td>
+                        <td className="px-2 py-2 align-top">
+                          {subtitle.startTime}
+                        </td>
+                        <td className="px-2 py-2 align-top">
+                          {subtitle.endTime}
+                        </td>
+                        <td className="px-2 py-2 align-top">{subtitle.text}</td>
+                      </tr>
+                    ))}
+                  </tbody>
+                </table>
+              ) : (
+                <p className="p-4 text-sm text-muted-foreground">
+                  {t("transcriptImport.emptyPreview")}
+                </p>
+              )}
+            </div>
+          </div>
+        </div>
+
+        <DialogFooter>
+          <DialogClose asChild>
+            <Button variant="outline">{t("dialog.cancel")}</Button>
+          </DialogClose>
+          <Button onClick={handleImport} disabled={importDisabled}>
+            <IconFileText />
+            {t("transcriptImport.importButton")}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/lib/transcript-segmentation.ts b/lib/transcript-segmentation.ts
new file mode 100644
index 0000000..1efab4e
--- /dev/null
+++ b/lib/transcript-segmentation.ts
@@ -0,0 +1,136 @@
+import type { Subtitle } from "@/types/subtitle";
+import { secondsToTime } from "@/lib/utils";
+import { v4 as uuidv4 } from "uuid";
+
+export type TranscriptSegmentationMode =
+  | "lines"
+  | "sentences"
+  | "maxCharacters";
+
+export interface TranscriptSegmentationOptions {
+  mode: TranscriptSegmentationMode;
+  startTimeSeconds: number;
+  cueDurationSeconds: number;
+  gapSeconds: number;
+  maxCharactersPerCue?: number;
+}
+
+export const TRANSCRIPT_SEGMENTATION_DEFAULTS = {
+  mode: "lines" as const,
+  startTimeSeconds: 0,
+  cueDurationSeconds: 3,
+  gapSeconds: 0.2,
+  maxCharactersPerCue: 80,
+};
+
+const normalizeInlineWhitespace = (text: string): string =>
+  text.replace(/\s+/g, " ").trim();
+
+const getPositiveNumber = (value: number, fallback: number): number =>
+  Number.isFinite(value) && value > 0 ? value : fallback;
+
+const getNonNegativeNumber = (value: number, fallback: number): number =>
+  Number.isFinite(value) && value >= 0 ? value : fallback;
+
+const splitByLines = (text: string): string[] =>
+  text
+    .replace(/\r\n?/g, "\n")
+    .split("\n")
+    .map((line) => line.trim())
+    .filter(Boolean);
+
+const splitBySentences = (text: string): string[] => {
+  const normalized = normalizeInlineWhitespace(text);
+  if (!normalized) return [];
+  return (
+    normalized
+      .match(/[^.!?]+(?:[.!?]+|$)/g)
+      ?.map((sentence) => sentence.trim())
+      .filter(Boolean) ?? []
+  );
+};
+
+const splitByMaxCharacters = (
+  text: string,
+  maxCharactersPerCue: number,
+): string[] => {
+  const normalized = normalizeInlineWhitespace(text);
+  if (!normalized) return [];
+
+  const chunks: string[] = [];
+  let current = "";
+
+  for (const word of normalized.split(" ")) {
+    if (!current) {
+      current = word;
+      continue;
+    }
+
+    const candidate = `${current} ${word}`;
+    if (candidate.length <= maxCharactersPerCue) {
+      current = candidate;
+      continue;
+    }
+
+    chunks.push(current);
+    current = word;
+  }
+
+  if (current) {
+    chunks.push(current);
+  }
+
+  return chunks;
+};
+
+const splitTranscript = (
+  text: string,
+  options: TranscriptSegmentationOptions,
+): string[] => {
+  if (options.mode === "sentences") {
+    return splitBySentences(text);
+  }
+
+  if (options.mode === "maxCharacters") {
+    const maxCharactersPerCue = Math.floor(
+      getPositiveNumber(
+        options.maxCharactersPerCue ??
+          TRANSCRIPT_SEGMENTATION_DEFAULTS.maxCharactersPerCue,
+        TRANSCRIPT_SEGMENTATION_DEFAULTS.maxCharactersPerCue,
+      ),
+    );
+    return splitByMaxCharacters(text, maxCharactersPerCue);
+  }
+
+  return splitByLines(text);
+};
+
+export const segmentTranscriptToSubtitles = (
+  text: string,
+  options: TranscriptSegmentationOptions,
+): Subtitle[] => {
+  const cueDurationSeconds = getPositiveNumber(
+    options.cueDurationSeconds,
+    TRANSCRIPT_SEGMENTATION_DEFAULTS.cueDurationSeconds,
+  );
+  const gapSeconds = getNonNegativeNumber(
+    options.gapSeconds,
+    TRANSCRIPT_SEGMENTATION_DEFAULTS.gapSeconds,
+  );
+  const startTimeSeconds = getNonNegativeNumber(
+    options.startTimeSeconds,
+    TRANSCRIPT_SEGMENTATION_DEFAULTS.startTimeSeconds,
+  );
+
+  return splitTranscript(text, options).map((cueText, index) => {
+    const startSeconds =
+      startTimeSeconds + index * (cueDurationSeconds + gapSeconds);
+    return {
+      uuid: uuidv4(),
+      id: index + 1,
+      startTime: secondsToTime(startSeconds),
+      endTime: secondsToTime(startSeconds + cueDurationSeconds),
+      text: cueText,
+    };
+  });
+};
diff --git a/messages/de.json b/messages/de.json
index 816c7ed..4381893 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -24,7 +24,8 @@
     "downloadAsSrt": ".srt",
     "downloadAsVtt": ".vtt",
     "downloadAsTxt": ".txt",
-    "downloadAsCsv": ".csv"
+    "downloadAsCsv": ".csv",
+    "importTranscript": "Transkript importieren"
   },
   "controls": {
     "play": "Abspielen",
@@ -36,7 +37,8 @@
   "labels": {
     "loadSrtFile": "Eine .srt/.vtt-Datei laden",
     "or": "oder",
-    "startFromScratch": "Von vorne beginnen"
+    "startFromScratch": "Von vorne beginnen",
+    "importTranscript": "Transkript importieren"
   },
   "videoPlayer": {
     "loadFile": "Video- / Audiodatei laden",
@@ -100,6 +102,38 @@
       "increaseOneSecond": "Versatz um 1 Sekunde erhöhen"
     }
   },
+  "transcriptImport": {
+    "title": "Transkript importieren",
+    "description": "Fügen Sie Transkripttext ein oder laden Sie eine .txt-Datei, und prüfen Sie die erzeugten Untertitel vor dem Import.",
+    "defaultTrackName": "Transkript",
+    "fileLabel": "Textdatei",
+    "chooseFile": ".txt-Datei wählen",
+    "fileHint": "Transkriptdateien bleiben in Ihrem Browser.",
+    "pasteLabel": "Transkripttext",
+    "pastePlaceholder": "Transkripttext hier einfügen...",
+    "trackNameLabel": "Spurname",
+    "modeLabel": "Aufteilen nach",
+    "modeLines": "Zeilen",
+    "modeSentences": "Sätzen",
+    "modeMaxCharacters": "Max. Zeichen",
+    "durationLabel": "Untertiteldauer",
+    "gapLabel": "Abstand",
+    "startOffsetLabel": "Startversatz",
+    "maxCharactersLabel": "Max. Zeichen",
+    "destinationReplace": "Der Import ersetzt die leere Spur „{track}“.",
+    "destinationNewTrack": "Der Import erstellt eine neue Untertitelspur.",
+    "trackLimitReached": "Sie haben bereits 4 Spuren. Löschen Sie eine Spur oder wechseln Sie vor dem Import zu einer leeren Spur.",
+    "previewTitle": "Vorschau",
+    "cueCount": "{count, plural, =0 {Keine Untertitel} =1 {# Untertitel} other {# Untertitel}}",
+    "emptyPreview": "Fügen Sie Text ein oder wählen Sie eine .txt-Datei, um erzeugte Untertitel zu sehen.",
+    "importButton": "Untertitel importieren",
+    "table": {
+      "id": "ID",
+      "start": "Start",
+      "end": "Ende",
+      "text": "Text"
+    }
+  },
   "instructions": {
     "afterLoading": "Nach dem Laden der Untertitel und der Mediendatei:",
     "editText": "Klicken Sie auf den Untertiteltext oder die Zeitstempel, um Ihre Untertitel zu bearbeiten.",
diff --git a/messages/en.json b/messages/en.json
index 95f907d..1e2bd5f 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -24,7 +24,8 @@
     "downloadAsSrt": ".srt",
     "downloadAsVtt": ".vtt",
     "downloadAsTxt": ".txt",
-    "downloadAsCsv": ".csv"
+    "downloadAsCsv": ".csv",
+    "importTranscript": "Import transcript"
   },
   "controls": {
     "play": "Play",
@@ -36,7 +37,8 @@
   "labels": {
     "loadSrtFile": "Load a .srt/.vtt file",
     "or": "or",
-    "startFromScratch": "Start from scratch"
+    "startFromScratch": "Start from scratch",
+    "importTranscript": "Import transcript"
   },
   "videoPlayer": {
     "loadFile": "Load a video / audio file",
@@ -100,6 +102,38 @@
       "increaseOneSecond": "Increase offset by 1 second"
     }
   },
+  "transcriptImport": {
+    "title": "Import transcript",
+    "description": "Paste transcript text or load a .txt file, then preview draft subtitle cues before importing.",
+    "defaultTrackName": "Transcript",
+    "fileLabel": "Text file",
+    "chooseFile": "Choose .txt file",
+    "fileHint": "Transcript files stay in your browser.",
+    "pasteLabel": "Transcript text",
+    "pastePlaceholder": "Paste transcript text here...",
+    "trackNameLabel": "Track name",
+    "modeLabel": "Split by",
+    "modeLines": "Lines",
+    "modeSentences": "Sentences",
+    "modeMaxCharacters": "Max characters",
+    "durationLabel": "Cue duration",
+    "gapLabel": "Gap",
+    "startOffsetLabel": "Start offset",
+    "maxCharactersLabel": "Max characters",
+    "destinationReplace": "Import will replace the empty track “{track}”.",
+    "destinationNewTrack": "Import will create a new subtitle track.",
+    "trackLimitReached": "You already have 4 tracks. Delete a track or switch to an empty track before importing.",
+    "previewTitle": "Preview",
+    "cueCount": "{count, plural, =0 {No cues} =1 {# cue} other {# cues}}",
+    "emptyPreview": "Paste text or choose a .txt file to preview generated cues.",
+    "importButton": "Import cues",
+    "table": {
+      "id": "ID",
+      "start": "Start",
+      "end": "End",
+      "text": "Text"
+    }
+  },
   "instructions": {
     "afterLoading": "After loading the subtitles and media file:",
     "editText": "Click the subtitle text or timestamps to edit your captions.",
diff --git a/messages/yue.json b/messages/yue.json
index bcccf60..9f54364 100644
--- a/messages/yue.json
+++ b/messages/yue.json
@@ -24,7 +24,8 @@
     "downloadAsSrt": ".srt",
     "downloadAsVtt": ".vtt",
     "downloadAsTxt": ".txt",
-    "downloadAsCsv": ".csv"
+    "downloadAsCsv": ".csv",
+    "importTranscript": "匯入逐字稿"
   },
   "controls": {
     "play": "播放",
@@ -36,7 +37,8 @@
   "labels": {
     "loadSrtFile": "載入 .srt/.vtt 檔案",
     "or": "或",
-    "startFromScratch": "由頭開始"
+    "startFromScratch": "由頭開始",
+    "importTranscript": "匯入逐字稿"
   },
   "videoPlayer": {
     "loadFile": "載入影片 / 音訊檔案",
@@ -100,6 +102,38 @@
       "increaseOneSecond": "遲 1 秒"
     }
   },
+  "transcriptImport": {
+    "title": "匯入逐字稿",
+    "description": "貼上逐字稿文字，或者載入 .txt 檔案，匯入前可以預覽產生嘅字幕。",
+    "defaultTrackName": "逐字稿",
+    "fileLabel": "文字檔案",
+    "chooseFile": "揀 .txt 檔案",
+    "fileHint": "逐字稿檔案只會留喺你嘅瀏覽器。",
+    "pasteLabel": "逐字稿文字",
+    "pastePlaceholder": "喺度貼上逐字稿文字...",
+    "trackNameLabel": "字幕軌名",
+    "modeLabel": "分段方式",
+    "modeLines": "按行",
+    "modeSentences": "按句",
+    "modeMaxCharacters": "按最多字數",
+    "durationLabel": "字幕時長",
+    "gapLabel": "間隔",
+    "startOffsetLabel": "起始偏移",
+    "maxCharactersLabel": "最多字數",
+    "destinationReplace": "匯入會取代空白字幕軌「{track}」。",
+    "destinationNewTrack": "匯入會建立一條新字幕軌。",
+    "trackLimitReached": "你已經有 4 條字幕軌。匯入前請先刪除一條，或者切換到空白字幕軌。",
+    "previewTitle": "預覽",
+    "cueCount": "{count} 條字幕",
+    "emptyPreview": "貼上文字或者揀 .txt 檔案，就可以預覽產生嘅字幕。",
+    "importButton": "匯入字幕",
+    "table": {
+      "id": "ID",
+      "start": "起點",
+      "end": "終點",
+      "text": "文字"
+    }
+  },
   "instructions": {
     "afterLoading": "載入字幕同媒體檔案後：",
     "editText": "撳字幕文字或時間點嚟編輯字幕。",
diff --git a/tests/transcript-segmentation.test.ts b/tests/transcript-segmentation.test.ts
new file mode 100644
index 0000000..621f98b
--- /dev/null
+++ b/tests/transcript-segmentation.test.ts
@@ -0,0 +1,95 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import {
+  segmentTranscriptToSubtitles,
+  type TranscriptSegmentationOptions,
+} from "../lib/transcript-segmentation";
+
+const baseOptions: TranscriptSegmentationOptions = {
+  mode: "lines",
+  startTimeSeconds: 0,
+  cueDurationSeconds: 3,
+  gapSeconds: 0.2,
+};
+
+test("line mode ignores blank lines and creates default sequential timings", () => {
+  const subtitles = segmentTranscriptToSubtitles(
+    " First line \n\nSecond line\r\n  \nThird line  ",
+    baseOptions,
+  );
+
+  assert.deepEqual(
+    subtitles.map((subtitle) => subtitle.text),
+    ["First line", "Second line", "Third line"],
+  );
+  assert.deepEqual(
+    subtitles.map((subtitle) => [
+      subtitle.id,
+      subtitle.startTime,
+      subtitle.endTime,
+    ]),
+    [
+      [1, "00:00:00,000", "00:00:03,000"],
+      [2, "00:00:03,200", "00:00:06,200"],
+      [3, "00:00:06,400", "00:00:09,400"],
+    ],
+  );
+  assert.ok(subtitles.every((subtitle) => subtitle.uuid.length > 0));
+});
+
+test("sentence mode splits pasted paragraphs and normalizes whitespace", () => {
+  const subtitles = segmentTranscriptToSubtitles(
+    "Hello world.  How are you?\n\nFine!",
+    { ...baseOptions, mode: "sentences" },
+  );
+
+  assert.deepEqual(
+    subtitles.map((subtitle) => subtitle.text),
+    ["Hello world.", "How are you?", "Fine!"],
+  );
+});
+
+test("max character mode chunks at word boundaries", () => {
+  const subtitles = segmentTranscriptToSubtitles(
+    "One two three four five six seven",
+    { ...baseOptions, mode: "maxCharacters", maxCharactersPerCue: 13 },
+  );
+
+  assert.deepEqual(
+    subtitles.map((subtitle) => subtitle.text),
+    ["One two three", "four five six", "seven"],
+  );
+});
+
+test("max character mode keeps a single long word intact", () => {
+  const subtitles = segmentTranscriptToSubtitles(
+    "supercalifragilistic short words",
+    { ...baseOptions, mode: "maxCharacters", maxCharactersPerCue: 8 },
+  );
+
+  assert.deepEqual(
+    subtitles.map((subtitle) => subtitle.text),
+    ["supercalifragilistic", "short", "words"],
+  );
+});
+
+test("timing options control start offset, duration, and gap", () => {
+  const subtitles = segmentTranscriptToSubtitles("A\nB", {
+    ...baseOptions,
+    startTimeSeconds: 10,
+    cueDurationSeconds: 2.5,
+    gapSeconds: 0.5,
+  });
+
+  assert.deepEqual(
+    subtitles.map((subtitle) => [subtitle.startTime, subtitle.endTime]),
+    [
+      ["00:00:10,000", "00:00:12,500"],
+      ["00:00:13,000", "00:00:15,500"],
+    ],
+  );
+});
+
+test("empty input returns no cues", () => {
+  assert.deepEqual(segmentTranscriptToSubtitles(" \n\t ", baseOptions), []);
+});