diff --git a/src/main/download-completion.ts b/src/main/download-completion.ts
new file mode 100644
index 0000000..a11430f
--- /dev/null
+++ b/src/main/download-completion.ts
@@ -0,0 +1,132 @@
+import { ALLOCATION_UNIT_SIZE } from "./constants";
+
+export type DownloadCompletionSource =
+  | "content-range"
+  | "content-length"
+  | "provider-metadata"
+  | "stream-end";
+
+export type DownloadCompletionPlan = {
+  expectedTotal: number | null;
+  source: DownloadCompletionSource;
+  canFinishEarly: boolean;
+};
+
+export function planDownloadCompletion(args: {
+  existingBytes: number;
+  responseStatus: number;
+  contentLength: number;
+  totalFromRange: number | null;
+  knownTotal: number | null;
+  correctedTotal: number | null;
+}): DownloadCompletionPlan {
+  const existingBytes = Math.max(0, Math.floor(Number(args.existingBytes) || 0));
+  const responseStatus = Math.floor(Number(args.responseStatus) || 0);
+  const contentLength = Math.max(0, Math.floor(Number(args.contentLength) || 0));
+  const totalFromRange = Number.isFinite(args.totalFromRange || NaN)
+    ? Math.max(0, Math.floor(args.totalFromRange || 0))
+    : 0;
+  const correctedTotal = Number.isFinite(args.correctedTotal || NaN)
+    ? Math.max(0, Math.floor(args.correctedTotal || 0))
+    : 0;
+  const knownTotal = Number.isFinite(args.knownTotal || NaN)
+    ? Math.max(0, Math.floor(args.knownTotal || 0))
+    : 0;
+
+  if (correctedTotal > 0) {
+    return {
+      expectedTotal: correctedTotal,
+      source: totalFromRange > 0 ? "content-range" : "content-length",
+      canFinishEarly: true
+    };
+  }
+
+  if (totalFromRange > 0) {
+    return {
+      expectedTotal: totalFromRange,
+      source: "content-range",
+      canFinishEarly: true
+    };
+  }
+
+  if (contentLength > 0) {
+    return {
+      expectedTotal: responseStatus === 206 ? existingBytes + contentLength : contentLength,
+      source: "content-length",
+      canFinishEarly: true
+    };
+  }
+
+  if (knownTotal > 0) {
+    return {
+      expectedTotal: knownTotal,
+      source: "provider-metadata",
+      canFinishEarly: false
+    };
+  }
+
+  return {
+    expectedTotal: null,
+    source: "stream-end",
+    canFinishEarly: false
+  };
+}
+
+export function validateDownloadedFileCompletion(args: {
+  actualBytes: number;
+  plan: DownloadCompletionPlan;
+}): {
+  ok: boolean;
+  totalBytes: number;
+  acceptedMetadataMismatch: boolean;
+  error?: string;
+} {
+  const actualBytes = Math.max(0, Math.floor(Number(args.actualBytes) || 0));
+  const expectedTotal = Number.isFinite(args.plan.expectedTotal || NaN)
+    ? Math.max(0, Math.floor(args.plan.expectedTotal || 0))
+    : 0;
+
+  if (
+    expectedTotal > 0 &&
+    (args.plan.source === "content-range" || args.plan.source === "content-length") &&
+    actualBytes + ALLOCATION_UNIT_SIZE < expectedTotal
+  ) {
+    return {
+      ok: false,
+      totalBytes: expectedTotal,
+      acceptedMetadataMismatch: false,
+      error: `download_underflow:${actualBytes}/${expectedTotal}`
+    };
+  }
+
+  if (actualBytes <= 0 && expectedTotal > 0) {
+    return {
+      ok: false,
+      totalBytes: expectedTotal,
+      acceptedMetadataMismatch: false,
+      error: `download_underflow:${actualBytes}/${expectedTotal}`
+    };
+  }
+
+  if (args.plan.source === "provider-metadata") {
+    return {
+      ok: true,
+      totalBytes: actualBytes,
+      acceptedMetadataMismatch: expectedTotal > 0 && Math.abs(actualBytes - expectedTotal) > ALLOCATION_UNIT_SIZE
+    };
+  }
+
+  if (args.plan.source === "stream-end") {
+    return {
+      ok: true,
+      totalBytes: actualBytes,
+      acceptedMetadataMismatch: false
+    };
+  }
+
+  return {
+    ok: true,
+    totalBytes: Math.max(actualBytes, expectedTotal),
+    acceptedMetadataMismatch: false
+  };
+}
diff --git a/src/main/download-manager.ts b/src/main/download-manager.ts
index be29d26..36b2843 100644
--- a/src/main/download-manager.ts
+++ b/src/main/download-manager.ts
@@ -50,6 +50,7 @@ function releaseTlsSkip(): void {
   }
 }
 import { cleanupCancelledPackageArtifactsAsync, removeDownloadLinkArtifacts, removeSampleArtifacts } from "./cleanup";
+import { planDownloadCompletion, validateDownloadedFileCompletion } from "./download-completion";
 import { AllDebridWebUnrestrictor, BestDebridWebUnrestrictor, DebridService, MegaWebUnrestrictor, RealDebridWebUnrestrictor, checkRapidgatorOnline, fetchAllDebridHostInfo, getAvailableDebridLinkApiKeys } from "./debrid";
 import { cleanupArchives, clearExtractResumeState, collectArchiveCleanupTargets, extractPackageArchives, findArchiveCandidates, hasAnyFilesRecursive, removeEmptyDirectoryTree, type ExtractArchiveFailureInfo } from "./extractor";
 import { validateFileAgainstManifest } from "./integrity";
@@ -8363,6 +8364,14 @@ export class DownloadManager extends EventEmitter {
           // Only add existingBytes for 206 responses; for 200 the Content-Length is the full file
           item.totalBytes = response.status === 206 ? existingBytes + contentLength : contentLength;
         }
+        const completionPlan = planDownloadCompletion({
+          existingBytes,
+          responseStatus: response.status,
+          contentLength,
+          totalFromRange,
+          knownTotal,
+          correctedTotal: correctedRealDebridTotal?.totalBytes || null
+        });
 
         const writeMode = existingBytes > 0 && response.status === 206 ? "a" : "w";
         logAttemptEvent("INFO", "HTTP-Antwort akzeptiert", {
@@ -8723,12 +8732,7 @@ export class DownloadManager extends EventEmitter {
               // Use totalBytes (from unrestrict or Content-Length header) as
               // primary check, fall back to raw contentLength for providers
               // that don't report fileSize (e.g. Mega-Debrid Web).
-              const expectedTotal = (item.totalBytes && item.totalBytes > 0) ? item.totalBytes : 0;
-              const expectedFromResponse = contentLength > 0 ? contentLength : 0;
-              if (expectedTotal > 0 && existingBytes + written >= expectedTotal) {
-                break;
-              }
-              if (expectedTotal === 0 && expectedFromResponse > 0 && written >= expectedFromResponse) {
+              if (completionPlan.canFinishEarly && completionPlan.expectedTotal && written >= completionPlan.expectedTotal) {
                 break;
               }
 
@@ -8870,6 +8874,20 @@ export class DownloadManager extends EventEmitter {
           }
         }
 
+        try {
+          const finalizedStat = await fs.promises.stat(effectiveTargetPath);
+          if (Number.isFinite(finalizedStat.size) && finalizedStat.size >= 0 && finalizedStat.size !== written) {
+            logAttemptEvent("WARN", "Dateigroesse nach Stream-Abschluss korrigiert", {
+              attempt,
+              previousWritten: written,
+              statSize: finalizedStat.size
+            });
+            written = finalizedStat.size;
+          }
+        } catch {
+          // ignore stat race; validation below will handle empty/missing files
+        }
+
         // Detect tiny error-response files (e.g. hoster returning "Forbidden" with HTTP 200).
         // No legitimate file-hoster download is < 512 bytes.
         if (written > 0 && written < 512) {
@@ -8900,21 +8918,37 @@ export class DownloadManager extends EventEmitter {
           }
         }
 
-        const exactLengthRequired = isLargeBinaryLikePath(item.fileName || effectiveTargetPath);
-        if (item.totalBytes && item.totalBytes > 0 && written < item.totalBytes) {
-          const shortfall = item.totalBytes - written;
+        const completionValidation = validateDownloadedFileCompletion({
+          actualBytes: written,
+          plan: completionPlan
+        });
+        if (!completionValidation.ok) {
+          const shortfall = Math.max(0, completionValidation.totalBytes - written);
           if (preAllocated) {
             try {
               await fs.promises.truncate(effectiveTargetPath, written);
             } catch { /* best-effort */ }
           }
-          logger.warn(`Download-Underflow: erwartet=${item.totalBytes}, erhalten=${written}, shortfall=${shortfall} fuer ${item.fileName}`);
-          if (exactLengthRequired || shortfall > ALLOCATION_UNIT_SIZE) {
-            item.downloadedBytes = written;
-            item.progressPercent = Math.max(0, Math.min(99, Math.floor((written / item.totalBytes) * 100)));
-            item.speedBps = 0;
-            throw new Error(`download_underflow:${written}/${item.totalBytes}`);
-          }
+          logger.warn(`Download-Underflow: erwartet=${completionValidation.totalBytes}, erhalten=${written}, shortfall=${shortfall} fuer ${item.fileName}`);
+          item.downloadedBytes = written;
+          item.progressPercent = completionValidation.totalBytes > 0
+            ? Math.max(0, Math.min(99, Math.floor((written / completionValidation.totalBytes) * 100)))
+            : 0;
+          item.speedBps = 0;
+          throw new Error(completionValidation.error || `download_underflow:${written}/${completionValidation.totalBytes}`);
+        }
+
+        if (completionValidation.acceptedMetadataMismatch) {
+          logger.warn(
+            `Provider-Groesseninfo verworfen, HTTP-EOF als vollstaendig akzeptiert: ` +
+            `${item.fileName} erwartet=${completionPlan.expectedTotal}, erhalten=${written}`
+          );
+          logAttemptEvent("WARN", "Provider-Groesseninfo weicht von finaler Dateigroesse ab", {
+            attempt,
+            expectedTotal: completionPlan.expectedTotal,
+            actualBytes: written,
+            source: completionPlan.source
+          });
         }
 
         // Truncate pre-allocated files to actual bytes written to prevent zero-padded tail
@@ -8926,6 +8960,7 @@ export class DownloadManager extends EventEmitter {
         }
 
         item.downloadedBytes = written;
+        item.totalBytes = completionValidation.totalBytes > 0 ? completionValidation.totalBytes : item.totalBytes;
         item.progressPercent = item.totalBytes ? Math.max(0, Math.min(100, Math.floor((written / item.totalBytes) * 100))) : 100;
         item.speedBps = 0;
         item.fullStatus = "Finalisierend...";
diff --git a/tests/download-manager.test.ts b/tests/download-manager.test.ts
index 8a3636f..29ad48f 100644
--- a/tests/download-manager.test.ts
+++ b/tests/download-manager.test.ts
@@ -7,6 +7,7 @@ import { EventEmitter, once } from "node:events";
 import AdmZip from "adm-zip";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { DownloadManager, extractArchiveNameFromExtractorLogMessage, getAuthoritativeRealDebridTotal, resolveArchiveItemsFromList } from "../src/main/download-manager";
+import { planDownloadCompletion, validateDownloadedFileCompletion } from "../src/main/download-completion";
 import { defaultSettings } from "../src/main/constants";
 import { parseDebridLinkApiKeys } from "../src/shared/debrid-link-keys";
 import { getProviderUsageDayKey } from "../src/shared/provider-daily-limits";
@@ -45,6 +46,38 @@ describe("resolveArchiveItemsFromList", () => {
   });
 });
 
+describe("download completion planning", () => {
+  it("does not allow early finish on provider metadata alone", () => {
+    expect(planDownloadCompletion({
+      existingBytes: 0,
+      responseStatus: 200,
+      contentLength: 0,
+      totalFromRange: null,
+      knownTotal: 192 * 1024,
+      correctedTotal: null
+    })).toEqual({
+      expectedTotal: 192 * 1024,
+      source: "provider-metadata",
+      canFinishEarly: false
+    });
+  });
+
+  it("accepts provider metadata mismatches after a clean stream end", () => {
+    expect(validateDownloadedFileCompletion({
+      actualBytes: 256 * 1024,
+      plan: {
+        expectedTotal: 192 * 1024,
+        source: "provider-metadata",
+        canFinishEarly: false
+      }
+    })).toEqual({
+      ok: true,
+      totalBytes: 256 * 1024,
+      acceptedMetadataMismatch: true
+    });
+  });
+});
+
 async function waitFor(predicate: () => boolean, timeoutMs = 15000): Promise<void> {
   const started = Date.now();
   while (!predicate()) {
@@ -1863,6 +1896,215 @@ describe("download manager", () => {
     }
   });
 
+  it("does not stop early on provider-only totals when the HTTP response is longer", async () => {
+    const root = fs.mkdtempSync(path.join(os.tmpdir(), "rd-provider-total-mismatch-"));
+    tempDirs.push(root);
+    const actual = Buffer.alloc(256 * 1024, 77);
+    const advertised = 192 * 1024;
+    let unrestrictCalls = 0;
+
+    const server = http.createServer((_req, res) => {
+      res.statusCode = 200;
+      res.setHeader("Transfer-Encoding", "chunked");
+      res.write(actual.subarray(0, 96 * 1024));
+      setTimeout(() => {
+        res.end(actual.subarray(96 * 1024));
+      }, 40);
+    });
+
+    server.listen(0, "127.0.0.1");
+    await once(server, "listening");
+
+    const address = server.address();
+    if (!address || typeof address === "string") {
+      throw new Error("server address unavailable");
+    }
+    const directUrl = `http://127.0.0.1:${address.port}/provider-mismatch`;
+
+    globalThis.fetch = async (input: RequestInfo | URL, init?: RequestInit): Promise<Response> => {
+      const url = typeof input === "string" ? input : input instanceof URL ? input.toString() : input.url;
+      if (url.includes("/unrestrict/link")) {
+        unrestrictCalls += 1;
+        return new Response(
+          JSON.stringify({
+            download: directUrl,
+            filename: "provider-mismatch.rar",
+            filesize: advertised
+          }),
+          {
+            status: 200,
+            headers: { "Content-Type": "application/json" }
+          }
+        );
+      }
+      return originalFetch(input, init);
+    };
+
+    try {
+      const manager = new DownloadManager(
+        {
+          ...defaultSettings(),
+          token: "rd-token",
+          outputDir: path.join(root, "downloads"),
+          extractDir: path.join(root, "extract"),
+          retryLimit: 1,
+          autoExtract: false,
+          autoReconnect: false
+        },
+        emptySession(),
+        createStoragePaths(path.join(root, "state"))
+      );
+
+      manager.addPackages([{ name: "provider-mismatch", links: ["https://dummy/provider-mismatch"] }]);
+      await manager.start();
+      await waitFor(() => !manager.getSnapshot().session.running, 25000);
+
+      const item = Object.values(manager.getSnapshot().session.items)[0];
+      expect(item?.status).toBe("completed");
+      expect(item?.downloadedBytes).toBe(actual.length);
+      expect(item?.totalBytes).toBe(actual.length);
+      expect(unrestrictCalls).toBe(1);
+      expect(fs.readFileSync(item.targetPath).equals(actual)).toBe(true);
+    } finally {
+      server.close();
+      await once(server, "close");
+    }
+  });
+
+  it("does not double-count resumed bytes when deciding early completion", async () => {
+    const root = fs.mkdtempSync(path.join(os.tmpdir(), "rd-resume-early-finish-"));
+    tempDirs.push(root);
+    const actual = Buffer.alloc(256 * 1024, 91);
+    const partialSize = 96 * 1024;
+    const pkgDir = path.join(root, "downloads", "resume-early-finish");
+    fs.mkdirSync(pkgDir, { recursive: true });
+    const targetPath = path.join(pkgDir, "resume-early-finish.mkv");
+    fs.writeFileSync(targetPath, actual.subarray(0, partialSize));
+    let unrestrictCalls = 0;
+    const starts: number[] = [];
+
+    const server = http.createServer((req, res) => {
+      const range = String(req.headers.range || "");
+      const match = range.match(/bytes=(\d+)-/i);
+      const start = match ? Number(match[1]) : 0;
+      starts.push(start);
+
+      if (start <= 0) {
+        res.statusCode = 500;
+        res.end("expected resume");
+        return;
+      }
+
+      const remaining = actual.subarray(start);
+      const firstChunkBytes = 64 * 1024;
+      res.statusCode = 206;
+      res.setHeader("Accept-Ranges", "bytes");
+      res.setHeader("Content-Range", `bytes ${start}-${actual.length - 1}/${actual.length}`);
+      res.setHeader("Content-Length", String(remaining.length));
+      res.write(remaining.subarray(0, firstChunkBytes));
+      setTimeout(() => {
+        res.end(remaining.subarray(firstChunkBytes));
+      }, 50);
+    });
+
+    server.listen(0, "127.0.0.1");
+    await once(server, "listening");
+
+    const address = server.address();
+    if (!address || typeof address === "string") {
+      throw new Error("server address unavailable");
+    }
+    const directUrl = `http://127.0.0.1:${address.port}/resume-early-finish`;
+
+    globalThis.fetch = async (input: RequestInfo | URL, init?: RequestInit): Promise<Response> => {
+      const url = typeof input === "string" ? input : input instanceof URL ? input.toString() : input.url;
+      if (url.includes("/unrestrict/link")) {
+        unrestrictCalls += 1;
+        return new Response(
+          JSON.stringify({
+            download: directUrl,
+            filename: "resume-early-finish.mkv",
+            filesize: actual.length
+          }),
+          {
+            status: 200,
+            headers: { "Content-Type": "application/json" }
+          }
+        );
+      }
+      return originalFetch(input, init);
+    };
+
+    try {
+      const session = emptySession();
+      const packageId = "resume-early-finish-pkg";
+      const itemId = "resume-early-finish-item";
+      const createdAt = Date.now() - 10_000;
+
+      session.packageOrder = [packageId];
+      session.packages[packageId] = {
+        id: packageId,
+        name: "resume-early-finish",
+        outputDir: pkgDir,
+        extractDir: path.join(root, "extract", "resume-early-finish"),
+        status: "queued",
+        itemIds: [itemId],
+        cancelled: false,
+        enabled: true,
+        createdAt,
+        updatedAt: createdAt
+      };
+      session.items[itemId] = {
+        id: itemId,
+        packageId,
+        url: "https://dummy/resume-early-finish",
+        provider: null,
+        status: "queued",
+        retries: 0,
+        speedBps: 0,
+        downloadedBytes: partialSize,
+        totalBytes: actual.length,
+        progressPercent: Math.floor((partialSize / actual.length) * 100),
+        fileName: "resume-early-finish.mkv",
+        targetPath,
+        resumable: true,
+        attempts: 0,
+        lastError: "",
+        fullStatus: "Wartet",
+        createdAt,
+        updatedAt: createdAt
+      };
+
+      const manager = new DownloadManager(
+        {
+          ...defaultSettings(),
+          token: "rd-token",
+          outputDir: path.join(root, "downloads"),
+          extractDir: path.join(root, "extract"),
+          retryLimit: 1,
+          autoExtract: false,
+          autoReconnect: false
+        },
+        session,
+        createStoragePaths(path.join(root, "state"))
+      );
+
+      await manager.start();
+      await waitFor(() => !manager.getSnapshot().session.running, 25000);
+
+      const item = manager.getSnapshot().session.items[itemId];
+      expect(item?.status).toBe("completed");
+      expect(item?.downloadedBytes).toBe(actual.length);
+      expect(item?.totalBytes).toBe(actual.length);
+      expect(unrestrictCalls).toBe(1);
+      expect(starts).toEqual([partialSize]);
+      expect(fs.readFileSync(targetPath).equals(actual)).toBe(true);
+    } finally {
+      server.close();
+      await once(server, "close");
+    }
+  });
+
   it("assigns unique target paths for same filenames in parallel", async () => {
     const root = fs.mkdtempSync(path.join(os.tmpdir(), "rd-dm-"));
     tempDirs.push(root);