These five speech recognition services automatically create captions that can make the videos you share for work more accessible.
With the general availability of speech-to-text transcription services from Google, Microsoft, IBM, and Amazon, developers can build speech-to-text capabilities into apps. Thanks to this speech recognition software, you can add captions to videos automatically.
Video captions make recorded content accessible to more people—captions can help people understand video when the environment is noisy, recorded audio is unintelligible, the sound is muted, or the listener can’t otherwise hear the audio playback.
The following apps will accurately transcribe most of your words, but you may still need to edit and correct technical terms, proper names, and sporadic errors. As of February 2019, in my experience, no service will add proper punctuation consistently.
For Android devices, AutoCap offers automatic video captions and subtitles. You can either record a video or select an existing video to caption. By default, the system auto-selects a word to emphasize in yellow within each group of captions (Figure A); you can manually edit the captions and adjust the emphasized word.
In my experience, AutoCap doesn’t work on every Android device. On a Nokia 7.1 with Android 9 Pie, the app opened but would stall during the caption application process. On an Honor 7x with Android 9 Pie, captioning completed as expected.
AutoCap is free, although the service will add its logo to your exported video. A one-time payment of $1.49 lets you remove the logo from a video, or you can subscribe for $3.99 per month.
Caption This ($2.99 for iOS devices) offers the options to auto-caption video as you record or to auto-create captions for previously recorded video. The app also works with video in portrait, landscape, or square aspect ratios (Figure B). Caption This lets you change the font and font size, as well as choose from several different background colors. Caption text can be either black or white.
When you open the app, you can either start to record or select a video. The app creates captions, which you can edit and adjust, and then export the completed video. When you return to the app, you’ll repeat the same process, since the app doesn’t offer a way to preserve work in process (as of February 2019). In my sample test, captioning stopped a few words before the end of the recorded video.
Clips, a free iOS app from Apple, allows you to capture captions as you speak; more importantly, you can access and edit the caption text to correct any errors (Figure C). As of February 2019, you can select from among 11 preset ways to display the text.
Clips has three notable limitations: It only captures square format video, it only works on iOS devices, and you have to use the app to record—meaning, you can’t import video from other sources into Clips for captioning.
Auto-Captioning is one of many browser-based video editing features Kapwing provides. Select the feature, upload your video, and then edit the auto-transcribed captions. Export your work when you’re done (Figure D).
You may use Kapwing at no charge, although the service will add its logo to your exported video. A one-time payment of $6 lets you remove the logo from a video, or you can subscribe for $20 per month to use all of the Kapwing tools logo-free.
YouTube auto-captions videos uploaded to the service. As the owner of the video, you may either edit or choose to upload a separate file with custom captions (Figure E).
Unlike every other app mentioned here, the service is really only intended to apply captions to videos hosted at YouTube. Native YouTube tools don’t make it easy to caption and export your captioned video file. You can download your own video or the auto-created captions as separate files, not as a single video file with captions displayed.
What method has worked best for you to add captions to video? Have you found automated speech recognition tools combined with manual edits to work well? Or do you rely on a service and/or human transcriptions? Let me know either in the comments or on Twitter (@awolber).