Add Subtitles to an Instagram Video Post

Feed shapes Instagram accepts

For years Instagram feed posts have come in three shapes, and the shape you choose changes how much room your subtitles have.

Square, 1:1

Commonly exported at 1080×1080. Balanced, and the same shape on every phone.

Portrait, 4:5

Commonly 1080×1350. Takes up more of the screen in the feed than square, which is why most feed videos use it.

Landscape

Up to a wide 1.91:1 shape. Small on a phone held upright; subtitles have to be bigger to read.

A vertical 9:16 clip posted on its own is generally treated as a Reel rather than a feed post, and that has its own layout; subtitles for Instagram Reels covers it. This page is about square and portrait videos, single or inside a carousel.

Single post, Reel or carousel?

Instagram has changed how videos are categorised more than once. At the time of writing, a single video posted from the app is usually shared as a Reel, while videos inside a carousel stay as carousel slides in the feed. In practice that means:

• A single 4:5 or square video may still appear in the Reels tab, where it is shown with space around it and Reels controls on top.
• A carousel keeps its videos in the feed shape, next to photos or other clips.
• Every slide in a carousel is shown in one shape. If your first item is 4:5 and a later video is square, Instagram fits or crops the later one to match.

That last point matters most for subtitles. Text placed near the edge of a slide that gets cropped can lose its first or last letters, or vanish.

Caption after you crop

The editor never resizes, crops or pads a video. Rendering keeps the source's resolution, frame rate and orientation, so a 1080×1350 file comes back 1080×1350. Two consequences:

• Crop to the final shape in a video editor or on your phone before you open the clip here. If Instagram does the cropping later, it decides what's lost, and subtitles near the edges are usually the casualty.
• Match every clip in a carousel to the same shape before captioning, so Instagram has nothing to fit.

Once the clip is in shape, "Show safe area" reads it and labels the guide 4:5 or 1:1. A clip that matches none of the standard shapes is labelled Custom, and its margins are chosen by how wide or tall the frame is. The guide only appears in the preview and is never drawn into the video.

Adding subtitles to a 4:5 or square clip

1. Open the editor on this page and choose the cropped clip: MP4, MOV, M4V, WebM or MKV. The style starts on the Classic look, white text with a black outline at the bottom.
2. Keep "Write the subtitles automatically with AI" on for a draft from the speech, or switch it off and import an SRT or VTT file, or type each line by pressing Enter at the playhead.
3. Watch the clip with the sound on and fix misheard words in the line list. Brand names and numbers deserve a second look.
4. Open Style, pick a preset and tick "Show safe area" to check the text sits inside the margins.
5. Click Render video, start the render from the summary, and keep the tab open until Download video appears.
6. Repeat for each video in the carousel, using the same preset and adjustments, then post the clips together.

Rendering happens in a desktop browser, and Instagram can be used from a computer for posting, so you don't have to move files to your phone unless you want to.

Where the text should go in a feed post

Feed posts carry far less overlay than Reels. The like, comment and share buttons and the caption text sit below the media, not on top of it. Over the picture you may see a small mute or audio icon and a tag icon in a corner, but the frame is otherwise clear. That changes the advice:

• Bottom placement works. The Classic, YouTube, Modern, Minimal, Cinema and High Contrast presets all sit at the bottom, inside the safe margin, and suit feed videos.
• Middle placement is optional. Social Media and Creator sit just under the centre, which suits punchy short clips but can cover faces in a portrait interview.
• Keep clear of corners. Corner icons are small, but a long left- or right-aligned line can run under one; centred text avoids them.

If one video in a carousel is close-up and another is wide, the same Bottom placement may land on a face in one and on the floor in the other. Use "Nudge up / down" on the clip that needs it rather than changing the style for all of them.

Size and wrapping in narrower frames

Text size is measured against the frame's shorter side. In a square video that's either side; in a 4:5 portrait it's the width. In both cases a size you like on one clip looks the same on another of that shape, even at different resolutions.

Narrower frames wrap sooner. A line that fits on one row in a 16:9 video may break into two in a 4:5 one. AI subtitles arrive as short single lines of about 32 characters, which usually fit, but hand-typed or imported lines can run longer; the editor warns above 42 characters and wraps automatically. If wrapping gets messy, shorten the text or split the line at the playhead.

For contrast on bright product shots or skin tones, a box behind the text is more reliable than an outline alone. The subtitle background guide compares outline, shadow, box and rounded box.

Before you post the carousel

• Every clip is cropped to the same shape, and the shape label in the safe-area option says 4:5 or 1:1.
• The same preset and adjustments were used on each clip, so the slides look like one post.
• No subtitle runs into a corner or under a face.
• Each MP4 has been played back once from your downloads folder.
• If you also want the words for Instagram's post text, Export SRT gives you the lines with timings; the video to text tool gives a plain transcript instead.

Drafts are saved in this browser for up to 5 videos, so a carousel of a few clips can be captioned over several sittings without losing work. If you need a subtitle file without rendering at all, the subtitle generator is the shorter route, and the Stories page covers the tap-through format.

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