What is an SRT file?

What is inside an SRT file

SRT is the file format of SubRip, a program for copying subtitles out of video. It holds only text and timing: the video and its sound stay in their own file, and the player draws the subtitles over the picture at the right moments. Each subtitle is a block of four parts:

1. A number, counting up from 1.
2. A timing line: the start time, the arrow --> and the end time, written as hours, minutes, seconds and milliseconds with a comma before the milliseconds: 00:00:02,827.
3. The text, usually one or two lines.
4. A blank line, which ends the block.

Two blocks look like this:

1
00:00:00,498 --> 00:00:02,827
Thanks for joining us today.

2
00:00:02,827 --> 00:00:06,383
Let's start with the schedule.

SRT has no header and no standard text encoding. Some players also read a few formatting tags, such as bold, italic, underline and color, but whether they appear depends on the player.

How to open and edit one

Open an SRT file in any plain-text editor. When you change it, keep the structure intact:

• Keep the numbers in order and each timing line directly under its number.
• Write times with exactly two digits for hours, minutes and seconds, three for milliseconds, and a comma before the milliseconds.
• Make sure each subtitle ends before the next begins, unless you want two on screen at once.
• Leave one blank line between blocks, and none inside the text.
• Save it as UTF-8 so accented letters and other scripts survive.

Players that load an SRT file alongside a video expect it to have the video's name: talk.mp4 and talk.srt, kept together. In a video editor or on a video site, add it as a subtitle or caption track instead.

Fix common problems

Every subtitle is early or late by the same amount. Shift the whole file with the subtitle timing tool. Enter how many seconds earlier or later, down to the millisecond, and download a corrected copy. Numbers, text and styling stay as they were, and cue lengths do not change.

The gap grows through the video. A fixed shift cannot fix drift, or a section removed from the middle. Make subtitles again from the final cut of the video.

Accents and symbols look garbled. The file was saved in one encoding and opened as another. Re-save it as UTF-8 in a text editor. StemVocal's subtitle timing tool and subtitle translator read UTF-8, UTF-16 marked with a byte-order mark, and Windows-1252.

The player skips or merges subtitles. Look for a missing blank line between blocks, a blank line inside a subtitle, or a timing line with a period instead of a comma.

Lines are too long to read. Split long subtitles into shorter ones. As a rule of thumb, a subtitle that stays up for a few seconds should hold no more than two short lines.

Make an SRT file from a video

1. Open the subtitle generator; SRT is already selected in its export menu.
2. Choose the video, or an audio file, and pick the spoken language or let StemVocal detect it.
3. Play it back with the captions over the picture, click any word to hear it, and correct names and misheard words.
4. Download the SRT file.

Each subtitle is timed from the words themselves. It lasts at most 6 seconds, holds at most 80 characters, splits into two balanced lines past 42 characters, and never overlaps the next one. Recordings up to 30 minutes are free, with 2 free StemVocal jobs each UTC day; longer files, up to 3 hours, use credits.

To translate an SRT file you already have, use the subtitle translator: every subtitle keeps its number and timing. To put the words on the picture permanently, add subtitles to the video instead.

SRT or VTT?

SRT suits video editors and upload forms; VTT suits web video players. WebVTT grew out of SRT: it adds a WEBVTT first line, uses a period before the milliseconds, and adds positioning and styling. The VTT file guide compares the two side by side and shows how to convert SRT to VTT by hand.

Sources: Library of Congress, "SubRip Subtitle format (SRT)"; MDN Web Docs, "Web Video Text Tracks Format (WebVTT)". Checked October 11, 2026.