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Jay PadimalaMarch 20266 min read
AI Tools6 min read

How to Add Auto Captions to TikTok/Reels/Shorts for Free

Add auto captions to TikTok, Instagram Reels, and YouTube Shorts for free. AI-generated subtitles, no watermark.

1,800 words

Access and pricing

Supported tools include 5 free on-device uses per day, shared across eligible tools. On compatible devices, guest access needs no sign-in. Signed-in users also get 5 daily eligible on-device uses. AI and cloud processing use credits separately.

New accounts can claim 20 welcome credits once. Eligible offers in MiOffice can earn up to 80 reward credits; offer conditions apply.

Starter costs $6.99/month and includes 250 credits at each paid renewal plus unlimited eligible local processing. Unused credits roll over. The $2.99 Day Pass covers 24 hours of eligible local processing; AI and cloud credits are separate.

Compare tools using a representative file and inspect the export. Check supported formats, device compatibility, processing location and the displayed cost before starting. This article is published by MiOffice; consider its recommendations with that affiliation in mind.

Pricing

Access and pricing updated October 30, 2026. This editorial update does not indicate a new test run.

Why Captions Matter for Short-Form Video

85% of Facebook and Instagram videos are watched without sound. On TikTok, captioned videos see 40% more watch time on average. Captions are not optional for short-form content — they are essential for reach, engagement, and accessibility.

MiOffice Auto Captions uses Whisper AI on GPU servers to transcribe your audio and burn styled captions directly into the video. No watermark, no account, Monthly plans with credit rollover.

How to Add Auto Captions with MiOffice

  1. 1

    Record or Upload Your Video

    Record your TikTok, Reel, or Short, then go to the Auto Captions tool. Upload MP4, MOV, WebM, or AVI.

  2. 2

    AI Transcribes Your Audio

    Whisper AI processes your audio on GPU servers, generating accurate word-level timestamps. Files are deleted immediately after processing.

  3. 3

    Customize Font and Position

    Choose font size and position (top or bottom). Place captions at the bottom third for TikTok or top for Reels — whatever fits your style.

  4. 4

    Download and Post

    Download your captioned video as MP4 — no watermark. Upload directly to TikTok, Instagram, YouTube, or any platform.

MiOffice vs CapCut vs Kapwing vs Veed.io

FeatureMiOffice AICapCutKapwingVeed.io
Auto CaptionsWhisper AIBuilt-inBuilt-inBuilt-in
WatermarkNoNoYes (free tier)Yes (free tier)
PriceFree to tryFree$24/mo$18/mo
Signup RequiredNoYesYesYes
PrivacyDeleted immediatelyByteDance serversCloud storageCloud storage
PlatformWeb (any device)Web + mobileWeb onlyWeb only

Platform-Specific Sizing

TikTok (9:16)

1080 x 1920 pixels. Place captions in the bottom third, avoiding the comment and share button area on the right side.

Instagram Reels (9:16)

1080 x 1920 pixels. Keep captions above the bottom 250px to avoid being covered by the username, caption text, and music label.

YouTube Shorts (9:16)

1080 x 1920 pixels. Captions work best centered or in the lower third. Avoid the subscribe button and title area at the bottom.

Facebook Feed (1:1)

1080 x 1080 pixels. Square format for feed posts. Center captions vertically for best readability in the scroll feed.

Privacy & Security

  • --Processed on secure GPU servers. Your videos are processed on dedicated GPU infrastructure and never stored permanently.
  • --Deleted immediately after processing. Video files are purged from server memory as soon as you download the captioned result.
  • --No content analysis. We do not review, categorize, or use your video content for any purpose beyond caption generation.
  • --Encrypted transfer. All uploads and downloads use HTTPS/TLS encryption.

Process Your Video Now

MiOffice AI is an AI-powered digital workspace studio. Create, edit, convert, compress, collaborate, and share — video, audio, images, documents, scanning, notes, screen sharing, and file transfer. the full MiOffice catalog, all in one place.

Get StartedLocal and cloud processing have different privacy terms

Frequently Asked Questions

Can I add auto captions to TikTok videos for free?
Yes. MiOffice Auto Captions uses Whisper AI to transcribe your video audio and burn captions directly into the video. Upload your TikTok video, customize font and position, and download with captions — no watermark, Guest access on supported tools; AI requires sign-in and credits.
What video formats and sizes are supported?
MiOffice supports MP4, MOV, WebM, and AVI video formats. You can upload videos in any aspect ratio — 9:16 for TikTok/Reels/Shorts, 16:9 for YouTube, or 1:1 for Facebook and Instagram feed posts.
Do the captions have a watermark?
No. MiOffice does not add any watermark to your captioned videos. The output is clean and ready to upload directly to TikTok, Instagram, YouTube, or any other platform.
How accurate are the AI-generated captions?
MiOffice uses OpenAI Whisper for transcription, which achieves over 95% accuracy for clear English audio. It supports 90+ languages and handles background music, accents, and multiple speakers reasonably well.

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Jay Padimala

CEO & Founder

Jay Padimala is CEO and Founder of MiOffice, a product of JSVV SOLS LLC.

View all posts by Jay Padimala
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