Add Subtitles to Facebook Reels

Why a Reel needs the words in the picture

Facebook treats captions differently depending on what you publish. For a regular video post, Facebook's help describes adding a SubRip (.srt) file after posting, one file per language, with a naming rule for the language code; adding SRT captions to a Facebook video has those steps. Reels haven't offered that file upload in the same way. At the time of writing, the words on a Reel come either from Facebook's automatic captions, where they're available for the language and account, or from text that is already part of the video. Meta reworks these tools regularly, so check the composer on your own account, but don't plan a Reel around uploading a subtitle file.

How Reels get watched adds to the case. They appear in the Reels tab, in rows inside the main feed, and in suggestions for people who don't follow you, and Facebook commonly starts video playing silently as it scrolls into view. Someone who never taps for sound still needs to follow the clip. Text drawn into the frames meets them on every one of those surfaces.

Reel or regular video post?

Before you caption anything, decide which kind of post you're making, because the options differ.

Reel

Vertical, full-screen viewer with Facebook's buttons and text on top. Words come from burned-in text or Facebook's automatic captions. Can be recommended to people beyond your followers.

Regular video post

Any shape, played inside the feed or a larger viewer. Accepts SRT files after posting, in several languages, which viewers switch on or off.

A horizontal interview, a long event recording or anything that needs captions in two languages usually sits better as a regular post with SRT files; Export SRT in the editor gives you that file. A short vertical clip made to be discovered belongs in Reels with burned subtitles.

What Facebook draws over a Reel

In the Reels viewer, a column of buttons runs down the right side: reactions, comments, sharing and a menu. Across the bottom sit the Page or profile name with a follow button, your description text, which grows when tapped, and the audio label. The top carries navigation and a camera shortcut. Facebook has redesigned this layout several times and it lands differently on different phones, so a pixel template copied today may be wrong next quarter.

What stays true is the shape of the problem: the bottom band and the right edge are crowded, and the middle of the frame is calm. Social Media, the preset this page starts on, aims for that calm area. It uses Poppins at weight 800 and size 7, dark text on a near-opaque white rounded box, anchored to Middle and nudged 12% below centre, with lines held to 80% of the safe width so they don't reach the button column.

"Show safe area" draws a guide for the frame's shape. On a 9:16 clip it leaves about 8% at each side, 12% at the top and 16% at the bottom. It's a general margin, not Facebook's own map, and it shows only in the preview; nothing from it reaches the downloaded video.

How to caption a Facebook Reel

1. Open the editor on this page and choose the vertical clip from your computer: MP4, MOV, M4V, WebM or MKV. Social Media is already selected under Style.
2. Get the subtitles: leave "Write the subtitles automatically with AI" on, or switch it off and use Import SRT / VTT, or press Enter at the playhead and type.
3. Play the clip with the sound muted and read only the captions. Anything you can't follow that way, rewrite.
4. Tick "Show safe area". Where a line covers a face or a product, drag the "Nudge up / down" slider; positive values move the block up, negative values move it down.
5. Click Render video, start it from the summary, keep the tab open, and click Download video when it's ready.
6. Post the MP4 as a Reel from the Facebook app, or from a computer where your account offers Reel uploads. If the composer offers automatic captions, leave them off for this clip so the words don't appear twice.

Cross-posting from Instagram

Plenty of Facebook Reels begin on Instagram. With accounts linked in Meta's Accounts Center, Instagram can offer to share a Reel to Facebook as well. Burned subtitles are pixels, so they arrive exactly as you designed them. Captions that an app generates itself are produced by that app; don't assume a caption setting on Instagram follows the Reel to Facebook.

The two overlays are similar but not identical. Placing text just under the middle clears both, which is why one render usually serves both apps. Instagram adds concerns Facebook doesn't have, such as the crop of the profile grid; subtitles for Instagram Reels covers those. The same file can also go to TikTok with captions or to YouTube as a Short; check each overlay once before posting.

Choosing a look that reads on Facebook

Facebook Reels reach a broad mix of viewers on a broad mix of phones, so legibility matters more than trend. Some options:

• Social Media: the default here, dark text on a white box, readable over almost any footage.
• High Contrast: yellow Noto Sans on solid black, the safest choice for bright outdoor viewing or older screens.
• Creator: bold yellow Montserrat in capitals with a thick outline, anchored to Middle and nudged a little lower than Social Media. Punchy, but capitals slow reading on longer lines.

Be clear about what static subtitles can do. Each line appears and disappears whole; there is no word-by-word highlighting, bounce or pop-in effect. If your style depends on animated words, that has to come from an app editor. Subtitle styles shows all eight presets side by side.

Size is measured against the frame's shorter side, which on a vertical clip is its width, so a size that looks right on a 720-wide draft looks the same on a 1080-wide master.

When the clip isn't vertical

The editor doesn't crop, pad or reframe. A 16:9 clip renders as 16:9 at its original resolution, and inside a full-screen vertical viewer it plays small with empty space around it, taking your subtitles down with it. Reframe the footage to 9:16 in a video editor first, then caption the vertical export; subtitles for vertical video covers that order of work. If the footage has to stay wide, publish it as a regular video post and attach the exported SRT instead.

Before you press Share

Run through this list with the downloaded MP4 on a phone, not just in the preview:

• The first caption appears with the first spoken word, and the opening second makes sense silently.
• No line is hidden by the buttons on the right or by your description at the bottom when it's expanded.
• Names, prices and place names are spelled the way your customers expect.
• Facebook's automatic captions are off for this post, if the composer offered them.
• The words still work for viewers who can't hear the audio at all; accessible social media video has more on that.

Want the subtitles in another language too? Set "Subtitle language" before running AI subtitles, or translate the whole video with the video translator. For a subtitle file without rendering a video, the subtitle generator is quicker.

About the subtitle editor on this page

Opens

MP4, MOV, M4V, WebM, MKV videos your browser can decode

Subtitles from

AI (from the speech, optionally translated into one of 21 languages), an SRT or VTT file, or typing them in

You download

An MP4 with the subtitles drawn into the picture at the original resolution and frame rate, plus SRT and VTT files

Cost

Editing, styling, rendering and SRT/VTT export are free, with no account and no watermark. AI subtitles cost 1 credit per minute (5-credit minimum per video); signing in with Google gives 100 free credits and accounts get 10 free credits a day

Privacy

The video never leaves your device and is rendered in your browser. Only for AI subtitles is the audio sent, over HTTPS, and it is deleted within 30 minutes of delivery

Rendering needs

Chrome or Edge 94+, Safari 16.4+, or Firefox 130+ on a computer. Editing and SRT/VTT export work in any current browser