Add Subtitles to Video Online

To add subtitles to a video online for free, upload the clip to EchoWave, click Auto-Subtitle to turn the speech into timed caption lines, correct any words, pick a caption style, and export. If you already have a subtitle file, add the SRT to your video instead of transcribing, or type the lines by hand when there is no speech to transcribe.

Subtitles follow the speech. For a title, a label or a call to action that is not dialogue, add text to the video as a separate layer in the same editor.

How to add subtitles to a video on iPhone, Android, or a computer

EchoWave runs in the browser, so the route is the same on every device. There is no app to install.

1. Open echowave.io in Safari, Chrome, Edge or Firefox and tap Upload Video.
2. Add your video from the camera roll, gallery or a folder.
3. Create the subtitles. Tap Auto-Subtitle, upload an SRT or VTT file, or type the lines.
4. Fix the wording and timing. Correct misheard names, split a long line, merge two short ones, and move a cue a few frames until it lands with the voice.
5. Style and export. Choose a caption style, drag the text where it reads best, and export the MP4 back to your device.

On iPhone or iPad

Open echowave.io in Safari, choose the clip from Photos, and edit the lines with the on-screen keyboard. The exported MP4 saves to your phone, ready to post.

On Android

Use Chrome or any current mobile browser. Upload from the gallery, caption the clip, and export a vertical MP4 for TikTok, Reels or Shorts.

On Windows, Mac or Chromebook

Follow the same five steps in a desktop browser. The bigger screen gives you a wider timeline, which makes retiming cues and placing captions quicker.

AI subtitle generator: add subtitles automatically

The built-in AI subtitle generator, Auto-Subtitle, listens to the audio track, detects the spoken language, and writes caption lines with a timestamp on every word. It then splits the transcript into short cues that appear and disappear with the speech, which is the difference between a transcript and subtitles you can read. Auto-Subtitle transcribes speech in 50+ languages, and translation covers 86 on a paid plan.

The AI subtitle generator is free to use: generating the subtitles, correcting them and burning them into the video cost nothing, and free exports are 720p with a small EchoWave badge. Downloading the subtitles as a separate SRT or VTT file is part of a paid plan.

What affects the result

Clear speech recorded close to the mic gives the cleanest first draft. Loud music under the voice, people talking over each other, and unusual names or jargon all mean more words to correct, as with any speech recognition. Every line stays editable, so a misheard word takes a few seconds to fix.

Word timing makes the styling possible

Because each word carries its own time, the editor can highlight words one at a time for karaoke-style captions and keep everything in sync after you change the wording. For a dedicated walkthrough of styled auto captions, see the caption generator.

Translate your subtitles into other languages

Once the speech is transcribed, the subtitle translator turns the caption track into another language and keeps the original timing, so you only review the wording. You can also show both languages at once, with the translated line under the original in the same caption box. Translation is part of a paid plan.

The same flow works for incoming footage: transcribe an interview or lecture in its original language, translate the lines into English, and check them before you export.

Style and animate your captions

Pick from 176 caption styles, then change anything: font, size, fill and outline color, a backing box or shadow for busy footage, and the position on the frame.

Word-by-word and karaoke captions

Highlight each word as it is spoken, fill words in a karaoke wipe, or pop them in one at a time. These suit TikTok, Reels and Shorts; keep motion subtle for tutorials and explainers.

Keep captions clear of platform buttons

On vertical 9:16 video, keep captions out of the bottom third of the frame, where the caption text, sound label and buttons sit. On 1:1 and 16:9 the lower center band is usually safe.

Burned-in subtitles or a separate SRT file?

Burned-in subtitles are drawn into the frames, so they show up everywhere. The hardcode subtitles page covers that route in detail. A separate file lets the viewer switch captions on or off; the SRT generator explains how to export one (SRT, VTT, TXT and JSON downloads are part of a paid plan).

Subtitles vs captions

Subtitles assume the viewer can hear and transcribe or translate the dialogue. Closed captions also note sound effects, music and who is speaking, for viewers who are deaf or hard of hearing. You can write either in EchoWave: type a sound cue like [door slams] on its own line where you need it.

Add subtitles to TikTok, Reels, YouTube and Facebook videos

TikTok, Instagram Reels and YouTube Shorts. Set the canvas to 9:16, burn the captions in, and keep them above the bottom third where each app puts its own caption text and buttons. Word-by-word styles hold attention on autoplay without sound.

YouTube. For a regular 16:9 upload you can burn captions in, or upload an SRT file in YouTube Studio so viewers can switch them on and off. YouTube reads that caption text, which gives it more to understand about the video.

Facebook and LinkedIn feeds. Feed video starts muted, so burned-in captions carry the message. A 1:1 or 4:5 canvas takes up more of the feed than 16:9.

Accessibility, lessons and training. Captions with speaker labels and sound cues let viewers who are deaf or hard of hearing follow along, and help learners read terms they have not heard before. For survey and research figures on who uses captions and why, see our caption and subtitle statistics.

Supported formats and devices

EchoWave opens the common video files you are likely to have: MP4 (H.264), MOV, WebM, MKV and AVI. Auto-Subtitle works from the audio track, so a clean voice recording gives the best first draft. Export at your source aspect ratio or switch to 9:16 for TikTok, Reels and Shorts, 1:1 for square posts, or 16:9 for YouTube.

The editor works in Chrome, Edge, Safari and Firefox on Windows, macOS, ChromeOS and Linux, and on iPhone, iPad and Android. Your projects stay private to your account.

How to add subtitles with FFmpeg

If you prefer the command line, FFmpeg can add an existing .srt file as a soft (toggleable) track:

ffmpeg -i input.mp4 -i subtitles.srt -c copy -c:s mov_text output.mp4

To burn the subtitles into the frames instead, use the subtitles filter:

ffmpeg -i input.mp4 -vf subtitles=subtitles.srt output.mp4

FFmpeg has no preview, no styling and no transcription, so you still need the subtitle file first.

Comparing caption tools? See our Submagic alternatives and Captions app alternatives guides.