How to Add Subtitles to a YouTube Video With an SRT File

YouTube can create automatic captions, but you don't control them. Names get misspelled, words are missed, and you can't fix them before viewers see them. Uploading your own subtitle file solves that: you decide exactly what appears on screen and when.

The most common subtitle file is SRT. This guide shows how to make one for free with Spokly's subtitle maker, check and fix it, and upload it to your video in YouTube Studio.

What an SRT file is

An SRT file is a plain text file. Each subtitle (called a cue) has a number, a start and end time, and the text:

1
00:00:00,000 --> 00:00:03,200
Hey everyone, welcome back to the channel.

2
00:00:03,400 --> 00:00:07,100
Today I want to show you how I edit
a full video in one afternoon.

That's all there is to it. Because it's plain text, almost every video platform and editor can read it. If you're wondering whether VTT would be a better choice, see SRT vs VTT. For YouTube, either works.

Step 1: Make the SRT file with Spokly

You need the video file (or just its audio) on your computer. If your video is already on YouTube and you don't have the file anymore, you can download your own upload from YouTube Studio first. Our guide on saving your own videos shows how.

1. Open the subtitle maker on the Spokly home page.
2. Drop your video or audio file onto the box. MP4, MOV, MP3, M4A, WAV, OGG and WebM all work, up to 60 minutes per file.
3. Choose the spoken language of the video.
4. Choose Fast or Accurate. Accurate takes longer but usually handles accents and noisy audio better.
5. Click Make subtitles for free.

Everything runs in your browser, so your video isn't uploaded anywhere. The first time, your browser downloads the speech model once; after that it starts right away.

When it's done, you'll see the list of cues, each with its number, its timing and its text.

Step 2: Check and fix the lines

Automatic transcription is good, but it's not perfect. Before you download, read through the cues while you think about the video:

• Names and brands: these are the most common mistakes. Fix the spelling of your name, your guests' names and any product names.
• Technical words: terms from your field may come out as similar-sounding everyday words.
• Missing words: if someone spoke over music or another person, a word or two may be missing.

Each cue's text is in its own box, so you can click it and type your fix. The timings stay as they are.

Spokly also keeps cues easy to read: when a cue is long, it's split into two lines at around 42 characters. If you want to break a line yourself, press Enter inside the box.

When you're happy with the text, click Download SRT. You'll get a file named after your video, for example my-video.srt.

Changing timings

The subtitle maker lets you edit the text of each cue, but not its timing. If a cue appears a little too early or too late, you have two options:

• Open the SRT file in any text editor (Notepad, TextEdit or VS Code) and change the numbers in the timing line. Keep the exact format: 00:00:03,400 --> 00:00:07,100.
• Upload the file to YouTube first, then adjust the timing in YouTube's own subtitle editor.

Step 3: Upload the SRT file in YouTube Studio

YouTube changes its menus from time to time, so the labels may be slightly different from what you see. The steps are:

1. Go to YouTube Studio and sign in to the channel that owns the video.
2. In the left menu, click Subtitles.
3. Click the video you want to add subtitles to.
4. If YouTube asks you to choose the video's language, choose the language that is spoken in the video and confirm.
5. Find the language row for your subtitles. If it's not there, click Add language and choose it.
6. In the Subtitles column of that row, click Add.
7. Choose Upload file.
8. Choose With timing, then Continue.
9. Select your .srt file.
10. Check the preview, then click Publish.

That's it. After a short time, viewers can turn on your subtitles with the CC button. If you upload subtitles in more than one language, viewers can choose between them in the settings menu.

With timing or without timing?

Always choose With timing for an SRT file from Spokly. "Without timing" is for a plain text transcript; YouTube then tries to match the text to the speech itself. Your SRT file already has the timings, so there's no reason to let YouTube guess.

Common mistakes (and how to fix them)

The subtitles are out of sync

This almost always happens when the video was changed after the subtitles were made. If you trimmed the intro, added a title card or cut a section, every cue after that point moves. The fix is simple: make the subtitles again from the final exported video, not from an earlier draft or the raw recording.

YouTube says the file is invalid

SRT is strict about its format. If you edited the file by hand, check that:

• every cue is separated from the next by one empty line;
• every timing line has the form 00:00:03,400 --> 00:00:07,100, with a comma before the milliseconds;
• the numbers count up from 1 without gaps.

If you're not sure what went wrong, download a fresh file from Spokly and redo your edits more carefully.

Strange characters instead of letters

This happens when a file isn't saved as UTF-8, which matters for accents and for languages like Arabic. Spokly saves its files as UTF-8. If you edit the file in a text editor, make sure it saves as UTF-8 too.

Subtitles in the wrong language row

If you upload English subtitles into the French row, viewers who choose French get English text. Always check that the language you choose in YouTube Studio matches the language of the file.

Lines that are too long to read

If a cue has a lot of text and only stays on screen for a moment, viewers can't read it in time. Split long sentences into two cues or shorten the wording. Short, clear lines are easier to follow on a phone screen.

Subtitles in other languages

Once you have the SRT file in the spoken language, you can make versions in other languages. Spokly's translate tool translates the text of each cue and keeps every number and timing exactly the same. It runs in Chrome on your computer.

Upload each translated file the same way, choosing its language in step 5.

AI tools for writing YouTube titles, descriptions and chapters from your transcript are coming soon to Spokly. Making and translating subtitles is free today.

FAQ

Do I need to sign up to make subtitles?

No. The subtitle maker works on the Spokly home page without an account, and your video stays on your computer.

Can I use the same SRT file on other platforms?

Yes. SRT is supported by many platforms and video editors. Some, like web video players, prefer VTT; the subtitle maker can download both formats from the same result.

How long can my video be?

Up to 60 minutes per file. For a longer video, export the audio in parts, make subtitles for each part, and combine them in a subtitle editor, or upload each part's file separately if the video is also split.

Will uploading my own subtitles replace YouTube's automatic captions?

Your uploaded subtitles appear as their own track, and viewers can choose them. You can also remove or hide automatic captions in YouTube Studio if you don't want them shown.