Spoolfield.ai
Auto captions for videos, highlighted word by word
Bring a video you’ve already finished, from a link or a file. Spoolfield listens to it, writes down what’s said and draws the captions into the picture, so each word stands out the moment it’s spoken. The video keeps its shape unless you choose a new one, and there’s nothing to install.
Sign up free for 15 credits, no card. Use only videos you own, are licensed to reuse, or have permission to use.
Caption a video in 3 steps
- Paste the video’s link under Your video and click Add, or choose Upload for an MP4, MOV, MKV or WebM file from your computer or phone.
- Choose Captions under Tool, then pick a Caption style and a Caption position. The Preview shows how the words will light up. To caption just one section, fill in From (optional) and To (optional).
- Check the price at the bottom and press Run. You get a new MP4 with the captions in the picture, ready to post.
Captions that fit the video you made
Four looks
Pop changes the color of the spoken word inside a short line, and Box does the same on a see-through panel. Word shows one large word at a time. Clean gives you plain subtitles.
The same shape as before
Shape starts on Keep, so a wide tutorial stays wide and a vertical clip stays vertical. Need a new frame too? Pick 9:16, 1:1, 4:5 or 16:9 and the reshaping happens in the same job.
In the language that’s spoken
Spoolfield works out the language from the speech and writes the captions in it, whether that’s Thai, English or one of dozens of others. Clear voices over quiet music give the most accurate words.
Words you’ve paid for are reused
Already ran a transcript or made Shorts from this video? While its files are kept, the words are free again, and the price line says words: free again.
Questions
Can I get an SRT file instead of captions in the picture?
Yes, from a different tool. Choose Transcript under Tool and you get a plain text file, an SRT subtitle file and a JSON file with the time of every word. Captions always draws the words into the video itself.
Which languages can it caption?
Thai, English and dozens more. You don’t have to pick the language: Spoolfield detects it from the speech, and the captions come out in that same language.
How much do auto captions cost?
1 credit per minute of audio to turn the speech into text, plus 1 credit per minute of captioned video you get back. Part of a minute counts as a full minute. The bar at the bottom shows the total before you press Run, and if the job fails, the credits come back.
What if the video has music and no talking?
Captions need speech. If nobody speaks, the job stops and you aren’t charged. Loud music under a voice can hide some words, so a clear voice gives the cleanest captions.
Caption the next video you post
15 credits are yours when you sign up, with no card.