Free auto captions for online video: a practical guide

A lot of people watch video on mute, on the bus or in a busy office. Captions tell them what is being said, and they make the message clear to viewers who speak another language. Platforms also search captions, so a caption file helps people find your video.

Automatic captions get you most of the way in minutes. The last part, checking the words and the timing, is what makes them look professional.

Speech recognition listens to the audio and writes down the words with a start and end time. The result is a list of caption lines. Quality depends on clear audio, a single speaker and a language the model knows well.

Editr lets you choose the engine. Whisper runs in your browser, so you do not send the audio anywhere. Deepgram is optional and uses your own key, and it supports many languages, including Hinglish.

Read the captions against the video once, from start to finish. Look for names, brands and technical words that the model may have missed. Fix them in the caption list. Click a line, change the words, and move on.

Keep lines short. Two lines on screen at most, and a few words per line for short-form video. Split a long line, or merge two short ones, from the same list.

Captions do two jobs: they carry the words, and they set the mood. Bold, high-contrast captions suit fast short videos. Quieter, smaller captions suit a talking head or a tutorial.

Editr has caption presets in several categories. Pick one close to what you want, then change the font, colour, outline and position. Word-by-word highlights help viewers follow along, and an entrance animation adds movement without distracting from the words.

Export the caption file when you want it outside the video, for example to upload it to a platform that takes subtitle files. SRT is the most widely accepted format. VTT suits web players. ASS keeps styling. TXT gives you a plain transcript, and JSON keeps the timing for other tools.

Burn the captions into the video when the platform does not accept subtitle files, or when the look matters more than the text being editable.

Before you post: captions are correct, the timing matches the speech, lines fit inside the safe area, the text is readable at phone size, and the file you uploaded is the version you checked.

Once you have a routine, captioning a short video takes a few minutes. Save a caption style you like, and reuse it.