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Add Subtitles

Automatically generate subtitles for a video using OpenAI Whisper AI transcription and burn them permanently into the video, creating a captioned version that works on all platforms

Our free add subtitles to video tool listens to your clip and writes the captions for you, then burns them permanently into the picture so they show on every platform. There is no manual typing and no subtitle file to prepare: upload your video, and the AI transcribes the spoken audio and lays clean, readable captions over the footage. It runs on OpenAI Whisper, the same speech recognition engine trusted for accurate transcription, and hands you back a standard MP4 with the words baked in. Whether you are captioning a talking-head clip for Instagram, a tutorial for YouTube, or an interview for LinkedIn, this is the quickest way to add captions to video without ever opening an editor. It is completely free, with no watermark on your video.

How to Add Subtitles to a Video Online

Adding subtitles to a video with File Tools Online takes a few quick steps, and you do not need Premiere, CapCut, or any desktop software. The AI does the listening, the writing, and the burning, so you never type a word or line up a single caption by hand.

  1. 1

    Upload your video

    Drag and drop your video into the box above, or click to browse and pick the file from your device. MP4, MOV, AVI, and MKV clips are all accepted.

  2. 2

    Whisper writes the captions

    The OpenAI Whisper engine listens to the spoken audio, transcribes it into timed captions, and burns them directly into the video frames. No script and no subtitle file needed.

  3. 3

    Download your captioned MP4

    Download the finished MP4 with the subtitles baked in, ready to post anywhere. Your file is processed securely and deleted automatically within 30 minutes.

Because the captions are burned straight into the picture, the video you download is self-contained: the words travel with it wherever it goes. There is no separate caption file to upload and no toggle for viewers to find. Upload once, and you get a ready-to-share captioned video in return.

Why Add Subtitles With File Tools Online

Most people watch video on mute, scrolling a feed where clips autoplay with the sound off. Subtitles are what keep those viewers watching. This tool makes captioning effortless: the AI writes and burns the words for you, so a job that used to mean hours in an editor becomes a single upload.

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AI Writes Them For You

No typing and no script. OpenAI Whisper listens to the speech in your clip and generates the captions automatically, start to finish.

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Wins Silent Autoplay

Burned-in captions show even when the sound is off, so muted feeds on Instagram, TikTok, and Facebook still deliver your message.

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Plays on Every Platform

The words are part of the picture, so they appear on any device, app, or player without a separate caption file to manage.

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Free, No Watermark

Auto-caption your video free online, with no trial limit and no watermark stamped across your footage.

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Private & Secure

Files are processed securely over an encrypted connection and automatically deleted within 30 minutes of upload.

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Works on Any Device

Runs online on Windows, Mac, Linux, Chromebook, Android, and iPhone. Nothing to download and nothing to install.

How AI Auto-Subtitles Work

When you add subtitles to a video here, two things happen in one pass. First, the audio track is fed to OpenAI Whisper, a speech recognition model that converts spoken words into text with accurate timing, so each caption appears in sync with what is being said. This is the same class of transcription technology used to caption podcasts and interviews, and it means you never have to write or upload a script. The AI does the listening and the writing.

Second, those timed captions are burned into the video, rendered permanently onto the frames themselves rather than stored as a separate track. This is what people mean by hardcoded or open captions. The trade-off matters: burned-in captions cannot be turned off by the viewer afterwards, and that is exactly what makes them so reliable. Because the words are part of the picture, they cannot fail to load and do not depend on the player supporting a caption format. The captioned MP4 plays the same everywhere, including silent autoplay feeds where a separate subtitle file would never appear. If you would rather have an editable text file you can tweak, retime, or restyle, use Extract Subtitles to pull a standalone SRT instead.

What You Can Caption

Almost any video with people speaking benefits from burned-in captions, and each use case solves the same problem: getting your message across when the sound is off. Here are the ones people reach for most often.

  • Social media clipsCaption Reels, TikToks, and Shorts so they land in muted, autoplaying feeds where most viewers never turn the sound on.
  • Tutorials and how-tosAdd on-screen text to instructional videos so steps stay clear even when viewers cannot listen along.
  • Interviews and podcastsTurn a filmed conversation into a captioned clip that is easy to follow and easy to share as a promo.
  • Marketing and promosMake ads and product clips accessible and scroll-stopping, with the key words visible at a glance.
  • AccessibilityGive deaf and hard-of-hearing viewers full access to your content with captions that are always on.
  • Course and training videoCaption lessons and onboarding material so learners can watch in any environment, quiet or noisy.

Related File Tools

File Tools Online offers more than 100 free tools to convert, edit, and manage your files. These are the ones people use most alongside the subtitle tool.

Burned-In Captions vs an Editable Subtitle File

There are two ways to put subtitles on a video, and they serve different needs. This tool makes burned-in captions: the words become part of the picture. The alternative is an editable subtitle file, usually an SRT, that sits alongside the video as a separate track a player can switch on or off. Knowing which you want saves time.

 Burned-in captions (this tool)Editable SRT file
Where the text livesPainted onto the video framesIn a separate .srt text file
Shows in muted autoplay feedsYes, always visibleOnly if the player loads and shows it
Can viewers turn it offNo, it is permanentYes, it is a toggle
Editable after the factNo, it is baked inYes, the text can be changed
Works everywhere with no setupYesDepends on the platform
Which toolAdd SubtitlesExtract Subtitles

If you want a clip that just works on every platform with no fiddling, burned-in captions are the answer, and that is what this tool produces. If you need the raw text to edit, translate, or hand to an editor, generate an SRT with Extract Subtitles instead.

A Free Alternative to Captioning Apps

Adding subtitles by hand in a desktop editor is slow work. In tools like Premiere Pro, Final Cut, or CapCut you transcribe the audio, split it into readable lines, nudge the timing of each caption, and style the text, all before you export. Auto-caption features in those apps often sit behind a subscription, and mobile caption apps frequently stamp a watermark on the result.

This tool removes all of that. Because the transcription and the burning happen automatically on our servers, you do not need any editing skill, any paid software, or a powerful computer. Upload your video and download a captioned MP4, with no watermark and nothing to install. It is a genuine free alternative for anyone who just needs the words on the screen. The account you sign in with is free to create.

Which Video Formats Can I Caption?

This tool accepts the common video formats people record and download, and always returns a standard MP4 with the captions burned in. Supported inputs include:

  • MP4, the standard format used by phones, cameras, and nearly every platform.
  • MOV (QuickTime), the format iPhones and Apple software record in.
  • AVI, a long-standing Windows video format found on older cameras and downloads.
  • MKV (Matroska), a high-quality container common with downloaded and archived video.

Whatever you upload, the output is the same dependable captioned MP4. Since the subtitles are hardcoded into the picture, that file plays with its captions on any device, app, or social platform. For the AI to caption accurately, the video needs clear, audible speech: the cleaner the audio, the sharper the transcription.

Tips for Adding Subtitles to Video

  • Use clean audio for the best captions. Whisper transcribes what it can hear, so clear speech with minimal background noise produces the most accurate subtitles. If your recording is noisy, run it through our audio extraction and cleanup steps first.
  • Trim to the part you need first. If you only want to caption a section of a long clip, trim it before you add subtitles so you get exactly the segment you want.
  • Caption after editing, not before. Do your cuts and edits first, then add subtitles to the final version so the words match the finished clip.
  • Need a smaller file to post? After captioning, run the MP4 through our video compressor to fit upload or file-size limits.
  • Want editable text instead? If you need to change the wording or translate it, generate an SRT with Extract Subtitles rather than burning the captions in.
  • Remember captions are permanent. Once they are burned in they cannot be removed cleanly, so keep your original video until you are happy with the captioned result.

Add Subtitles on Windows, Mac, and Mobile

Because this is an online tool, it works the same on every device. There is no program to install on Windows, no app to download on Mac, and nothing to add to your phone. You use the exact same page whether you are on a laptop, a Chromebook, an Android device, or an iPhone.

That makes it easy to add captions to a video on Mac, on a work computer where you cannot install software, or on your phone right before you post a clip. The transcription runs on our servers with the Whisper engine, so even a longer video is captioned reliably. All you need is a browser and an internet connection.

Is It Safe to Add Subtitles Online?

Yes. The videos people caption are often unreleased marketing clips, personal recordings, and work projects, so security is built in. Files are uploaded over an encrypted HTTPS connection, processed on a secure server, and automatically deleted within 30 minutes. Your video and its transcribed captions are never shared, sold, or reused.

Add Subtitles Frequently Asked Questions

How do I add subtitles to a video?

Upload your video to the tool above and the OpenAI Whisper engine listens to the spoken audio, writes the captions, and burns them permanently into the video. You then download a captioned MP4. There is no typing and no subtitle file to prepare, and nothing to install.

Do I need to type the subtitles or upload an SRT file?

No. The AI generates the subtitles for you by listening to the speech in your clip. You do not type anything and you do not upload your own subtitle file. If instead you want to produce an editable SRT text file from a video, use the Extract Subtitles tool.

Can I add subtitles to a video for free?

Yes. The File Tools Online subtitle tool is free to use, with no watermark added to your footage. Upload the video, let the AI caption it, and download the result.

Are the subtitles burned in or a separate track?

They are burned in, also called hardcoded or open captions. The words are rendered permanently onto the video frames, so they are part of the picture rather than a separate track a viewer can switch on or off.

Can the subtitles be turned off after they are added?

No. Burned-in captions are permanent and cannot be turned off by the viewer. That is exactly what makes them play everywhere, including muted autoplay feeds, since they never depend on the player loading a separate caption file.

Will the captions show in muted autoplay feeds?

Yes. Because the captions are baked into the picture, they appear even when the sound is off. That is the main reason to burn subtitles into social clips on Instagram, TikTok, and Facebook, where most video autoplays on mute.

How accurate are the auto-generated subtitles?

The tool uses OpenAI Whisper, a strong speech recognition model, so clear speech transcribes well. Accuracy depends on the audio: clean, audible speech with little background noise gives the best captions, while noisy or muffled recordings are harder to transcribe.

What video formats can I upload?

You can upload MP4, MOV, AVI, and MKV files. Whatever the input, the tool returns a standard MP4 with the subtitles burned in, ready to play with its captions on any device or platform.

Can I edit or restyle the captions afterwards?

Not on this tool, because the captions are burned in as part of the video. If you need editable, retimable text, generate an SRT file with Extract Subtitles instead, then edit that file in any subtitle editor.

How do I remove existing subtitles from a video?

If your video already has a separate subtitle track you want gone, use the Remove Subtitles tool to strip it out. Note that captions already burned into the picture cannot be cleanly removed, which is why it is worth keeping your original file.

Is my video safe when I add subtitles online?

Yes. Files are transferred over an encrypted connection, processed securely, and automatically deleted within 30 minutes. Your video and its captions are never shared or sold.

About Adding Subtitles to Video

Captions have gone from a nice extra to a requirement. Most social video is watched on mute, viewers scroll past anything they cannot follow at a glance, and accessibility expectations mean on-screen text is now standard. The problem has always been the effort: transcribing speech, breaking it into readable lines, and timing every caption is tedious work in a video editor.

This free online tool removes that effort with AI. It uses OpenAI Whisper to transcribe the spoken audio in your clip, then burns the resulting captions permanently into the video, producing a captioned MP4 that plays the same on every platform. Because the words are part of the picture, there is no separate file to manage and nothing for a viewer to switch off, which is precisely why burned-in captions are so dependable in silent, autoplaying feeds. Upload your video, let the AI caption it, and download a ready-to-share clip, free and with no watermark. If you ever need the text as an editable file rather than baked-in captions, reach for Extract Subtitles instead.