How to Add Subtitles to a Video (Automatically, for Free)

By Thiago · Updated September 25, 2026 · 3 min read

Subtitles used to mean hours of typing and syncing. Today speech recognition writes the first draft in about the time the video lasts, and your job is to check it, choose a look that is easy to read, and export it in the right format for where you will post it.

Two kinds of subtitles, and when to use each

A simple rule: if the platform has its own "upload subtitles" option, use a file. If people will watch in a feed with the sound off, burn the subtitles in so they cannot miss them.

Step 1: create the subtitles automatically

1. Open the auto subtitle generator and add your video. It accepts MP4, MOV, WEBM, MKV and AVI (and audio files) up to 5 minutes long.
2. Choose the language spoken in the video. "Detect automatically" works well, but picking the language yourself avoids surprises with very short clips or mixed languages.
3. Click "Generate subtitles". Speech recognition runs on our server and takes roughly as long as the video itself: a 2-minute clip takes about 2 minutes.

Lines are kept short (about 42 characters) so they are easy to read on a phone and never cover half of the screen.

Step 2: fix the mistakes

Automatic transcription is very good with clear speech, but it is not perfect. The usual mistakes are predictable, so you know where to look:

• Names and brands: people, companies, products and places the recognizer has never heard.
• Technical terms and slang.
• Words spoken over music or while several people talk at once.

In the editor, click any time stamp to jump to that moment, type the correction and watch the preview update as you type. You can also delete lines you do not want, like a "thanks for watching" at the end.

Step 3: choose a look people can read

Readable subtitles are more important than fancy ones. What works best on phones:

• High contrast: white or yellow text with a black outline, or light text on a dark box. The box style is the safest over busy or bright footage.
• Size: medium or large for vertical videos. Small text is fine for widescreen videos watched on a computer.
• Position: bottom is standard. In Reels and TikTok the bottom of the screen is covered by the caption and buttons, so the middle position is often a better choice.
• Capital letters give a bold social-media look with condensed fonts like Bebas Neue, but long sentences are easier to read in normal case.

The preview on the page uses the same fonts and the same measurements as the finished video, so what you see while choosing is what you get.

Step 4: export

For YouTube

Download the SRT file. In YouTube Studio, open the video, go to Subtitles, add the language, choose Upload file and pick With timing. Viewers can then turn the captions on, and the text also helps people find your video.

For Instagram, TikTok and WhatsApp

Click "Create video with subtitles". When it is ready, watch it on the page, and if you like it, download the MP4 and post it like any other video.

For a video editor

Most editors, such as Premiere Pro and DaVinci Resolve, can import an SRT file as a subtitle track, which you can then style there.

Tips for better automatic subtitles

• Record with the microphone close to the speaker. Clean audio matters more than video quality.
• Turn background music down during speech.
• If your video is longer than 5 minutes, split it into parts or subtitle the most important section.
• Already have a large video file? The video compressor can make it smaller before you upload it.