What Is an SRT File? A Practical Guide to SRT Subtitles
What an SRT subtitle file looks like, when to use it instead of burned-in captions, how to upload it to the main platforms and how to fix common errors.
Cameratel team
5 min read
Updated:
In this guide
An SRT file is a plain-text subtitle file: a numbered list of captions, each with a start time, an end time and the text to show. Video platforms read it and display the captions over your video, and viewers can usually turn them on or off. Because it's plain text, you can open and edit an SRT file in any text editor, and almost every major video platform accepts one.
What's inside an SRT file
Here's a complete SRT file with three captions:
1 00:00:00,000 --> 00:00:02,400 Here's the fastest way to light a video with one window. 2 00:00:02,600 --> 00:00:05,100 Turn your desk so the window is in front of you. 3 00:00:05,300 --> 00:00:08,200 Then switch off the ceiling light and look at the preview.
Each caption block has four parts:
| Part | Example | Rules |
|---|---|---|
| Number | 1 | Counts up from 1, one number per caption |
| Timecode | 00:00:00,000 --> 00:00:02,400 | Hours, minutes, seconds and milliseconds, with a comma before the milliseconds and an arrow between start and end |
| Text | One or two lines | Keep lines short; about 42 characters is a common maximum |
| Blank line | (empty) | Separates one caption from the next |
Save the file with the .srt extension and UTF-8 text encoding. Most SRT problems come from breaking one of these rules.
Open vs closed captions: burned-in text or a file?
| Question | Open captions (burned in) | Closed captions (SRT file) |
|---|---|---|
| What it is | Text drawn into the video picture | A separate file the player shows on top |
| Can viewers turn it off? | No | Usually yes |
| Works in every app? | Yes, the text travels with the video | Only where the platform accepts caption files |
| Editable after export? | No, you'd export the video again | Yes, edit the text file and upload it again |
| Translations | One language per video file | As many languages as you like |
Use open captions for short vertical videos that get reposted and shared. Use closed captions for YouTube, courses and anywhere viewers might want to switch them off or pick a language. Many creators do both: burned-in captions on the Reel, an SRT file on the YouTube upload. For the wider picture, see our auto captions guide.
How to upload an SRT file to YouTube, Facebook, LinkedIn and Vimeo
Menus change from time to time, but the basic flow on each platform stays the same.
YouTube
- Sign in to YouTube Studio and open Subtitles in the left menu.
- Select your video, click Add language and choose the language.
- Under Subtitles, click Add, then Upload file.
- Choose With timing, click Continue and select your .srt file.
- Click Save.
YouTube's own help page, Add subtitles and captions, lists the supported file types and the latest steps.
Open the video post or the video in your Page's content tools, find the subtitles and captions option and upload the file. Facebook expects the language in the file name, in the form filename.en_US.srt, so rename the file before you upload it.
When you post a video from a computer, look for the caption option in the video settings before you publish, and attach the .srt file there. Check the preview to confirm the captions appear before you post.
Vimeo
Open the video's settings, go to the captions and subtitles section, upload the .srt file and set its language and type (captions or subtitles).
For any platform not listed here, search its help center for "upload subtitles" or "caption file." Most accept SRT.
Platforms that need burned-in captions
Instagram Reels and Stories, TikTok and most messaging apps don't let you attach your own SRT file to a regular post. And when you send a video file directly, by message or email, the SRT doesn't travel with it. In those cases, burn the captions into the video. If you do, keep them inside the safe area of the frame, as explained in the video format and settings guide.
Cameratel gives you both from the same take: export the captions as an .srt file, or burn them into the video in one tap. The captions are generated from your script, so names and terms are already spelled correctly in either version. See how the auto captions feature builds them.
Common SRT errors and how to fix them
| Problem | Likely cause | Fix |
|---|---|---|
| Strange characters like "é" instead of "é" | File not saved as UTF-8 | Save the file again with UTF-8 encoding |
| Upload rejected | A period instead of a comma before the milliseconds, a missing blank line or a .txt extension | Fix the format and save as .srt |
| Every caption early or late by the same amount | The video was trimmed after the captions were made | Shift all timecodes by the same offset in a subtitle editor |
| Captions drift further out of sync over time | The captions belong to a different edit or frame rate | Export the captions again from the final video |
| Captions too long to read | Too much text per caption | Split them into one or two short lines |
| Some captions missing | A numbering gap or two captions merged together | Check that every block has a number, a timecode, text and a blank line |
Before you upload, play the video with its SRT file in a desktop media player that supports subtitles. A two-minute check catches most of these problems.
Translating an SRT file
Because an SRT file is plain text, translating it is straightforward:
- Export the SRT in the original language and make a copy.
- Translate only the text lines. Leave the numbers and timecodes untouched.
- Watch line lengths. Some languages run longer than English, so split long lines instead of cramming them.
- Save the copy as UTF-8 and add the language code to the file name, for example
video.es.srt. Facebook wants the formvideo.es_ES.srt. - Upload it as an additional language. YouTube, for example, lets one video carry subtitles in many languages.
- Ask a native speaker to watch the video with the translated captions before you publish.
If your captions come from Cameratel, the exported .srt already matches your script word for word, which makes it a clean starting point for translation.
Frequently asked questions
Can I upload an SRT file to Instagram or TikTok?
Not as a separate file for regular posts. For those apps, burn the captions into the video or use the platform's own caption tools.
Why does my SRT file show strange characters?
The file probably isn't saved as UTF-8. Open it in a text editor, save it again with UTF-8 encoding and upload it again.
What's the difference between SRT and VTT files?
Both are timed caption formats. WebVTT was designed for web players and supports more styling, while SRT is simpler and accepted almost everywhere.
Can I edit an SRT file myself?
Yes. It's plain text, so you can fix a word or a timing in any text editor. Keep the numbering, the arrow format and the blank lines between captions intact.