How to create an SRT file from a video
An SRT file pairs each spoken caption with a start and end time. You can create one without uploading the video, then use it on most video platforms and in many editing applications.
Before you start
Use the clearest copy of the video you have. Loud music, overlapping speakers, room echo, and very quiet dialogue all make automatic transcription less accurate. If you only need captions, video resolution has little effect; audio clarity matters far more.
CaptionKite accepts local files up to 2 GB and two hours. Chrome or Edge generally offers the broadest media and browser-AI compatibility.
1. Generate the first transcript
- Open the CaptionKite caption tool and choose Upload a file.
- Select your video or audio file, choose the spoken language, and start transcription.
- Leave the tab open while the model processes the audio. The first visit takes longer because the browser must download the speech model.
- When processing finishes, read through the transcript before downloading it.
The media is decoded and transcribed in your browser. The file itself is not sent to CaptionKite's servers.
2. Review words and timing
Automatic captions are a strong first draft, not a substitute for review. Check names, product terms, numbers, acronyms, and sentences spoken over noise. Read each caption while listening to the matching section of video.
- Break long thoughts at natural pauses.
- Avoid leaving a single short word on its own line.
- Keep enough on-screen time for a viewer to read comfortably.
- Preserve the speaker's meaning instead of rewriting their message.
3. Download and test the SRT
Choose Download SRT. Keep the .srt extension and, when a platform expects matching names, give the video and caption files the same base filename—for example, interview.mp4 and interview.srt.
Upload both files to your destination and preview the complete video. Confirm the first caption begins correctly, later captions have not drifted, and the final caption ends on time.
What is inside an SRT file?
1
00:00:02,400 --> 00:00:05,100
Welcome to this short tutorial.
2
00:00:05,700 --> 00:00:08,200
Today we will create captions.Each block contains a sequence number, a time range, and caption text. A blank line separates blocks. If you edit an SRT manually, keep that structure intact and save it as UTF-8 text.
What to do next
If your destination asks for WebVTT instead, CaptionKite can export that too. Read SRT vs. VTT before choosing, or continue with the guide to adding captions to an MP4.