Guide

How to make TikTok clips from a long video

To make TikTok clips from a long video, pick the moments that make sense on their own, crop them to vertical 9:16 (1080 × 1920), add captions, and make sure the first sentence says what the clip is about. You can do it by hand, one clip at a time, or with AI: in iaclips you paste a YouTube link or upload the video and get several vertical clips with captions, free for up to 30 minutes of video every 30 days.

Updated October 20, 2026

What does a TikTok clip need?

It has to be vertical, make sense with the sound off and without the full video, and say what it's about in the first seconds. Here's what to check, and what every iaclips clip already has:

What a TikTok clip needs, and what an iaclips clip has
What	For TikTok	In an iaclips clip
Format	Vertical 9:16. TikTok recommends vertical for its ads, at least 540 × 960 pixels (TikTok Ads help)	9:16, 1080 × 1920 pixels
Length	As long as the story needs to stand on its own, with no warm-up	Complete stories up to 3 minutes, or shorter clips up to 90 seconds
Captions	On screen, so it works with the sound off	Burned into the video, in 4 styles; 3 of them highlight the word being said
First seconds	The line that says what the clip is about	Cut at the start of the story; an optional title at the top
Post text	A caption and hashtags	A title, a description and hashtags in the video's language

How do I make TikTok clips with AI?

With iaclips, one long video turns into several clips at once. Step by step:

Paste a link or upload the video
On the iaclips home page, paste a YouTube link or upload the file (an interview, a class, a Zoom recording) and click Make clips. Sign in with your Google account; the free plan doesn't ask for a card.
Choose the length
Shorter (up to 90 s) for quick clips, or Complete stories (up to 3 min) when the topic needs more time. On the free plan each video can be up to 30 minutes: for a longer one, pick the part under From and To.
Choose the caption look
Highlight (the spoken word in color), Bold (all caps with a thick outline), Word box (the current word in a colored box) or Boxed (white on a dark background). Under Title on the video, At the top keeps the clip's title on screen; None leaves just the captions.
Process and wait for the email
Click Process. The app transcribes the video, finds the stories that stand on their own, sets each one's start and end, and crops them to vertical. We email you when they're ready.
Check each clip's first sentence
Open the clip: if the first sentence doesn't make sense on its own, click Start here on the sentence before or after it. Fix any misspelled word by clicking it.
Download and post to TikTok
Download the clip and copy its post text. In the TikTok app, tap Add post (+), then Upload, choose the clip, tap Next, paste the text and tap Post.

TikTok's steps are from its help center. You can also upload from a computer in your browser. On desktop, TikTok uploads the whole video without a trimming step, which is fine: your clip is already trimmed.

How do I make TikTok clips by hand?

With any video editor. It's the better choice if you only want one or two clips and already know which moments.

Find the moment: rewatch the video and note where each story starts and ends.
Trim it: in your browser, with nothing to install, using our free video trimmer.
Make it vertical 9:16: with our free crop tool, dragging the frame so whoever is talking stays in it.
Add captions: CapCut generates them with Captions > Auto captions > Generate; check them before you export.
Export it, then write the caption and hashtags.

By hand or with AI?

It depends on how many clips you need and how much control you want over each one. You can mix them: get the clips from iaclips and take the ones you want to polish into your editor.

Making TikTok clips by hand or with iaclips
	By hand (a video editor)	With AI (iaclips)
Who picks the moments	You, watching the video	The AI, from the transcript; you review
Captions	You generate and check them for each clip	Included, burned in; you fix single words
Vertical framing	You move it	Follows whoever is talking; or stays on one person, or shows the whole frame
Effects, music, B-roll	Yes, whatever your editor has	No
Cost	Free with the browser trimmer or CapCut	Free: 30 minutes of video every 30 days; Creator, $12 a month for 5 hours

What goes in the first seconds of a TikTok clip?

The line that says what the clip is about. If it opens with “so then…” or “like I said”, the viewer has no context.

Start on the question, the claim or the problem, not on the greeting or the intro.
Have captions on screen from the first second.
A title at the top tells people the topic before the speaker gets there. In iaclips, turn it on with Title on the video: At the top.
In TikTok's preview, check that the buttons on the right and the text at the bottom don't cover the captions.
If the clip already has captions burned in, don't add TikTok's own captions on top, or the text shows up twice.

How do I get several clips from one video?

With AI it all comes out at once: iaclips delivers every story it finds in the video, and Download all gets you every clip in one step. For more clips, under How many clips choose More clips, some less rounded; to keep only the best, Only the strongest.

The same clips work for Reels and Shorts, since they're vertical and 3 minutes or less. For YouTube, see how to turn a YouTube video into Shorts. If the video is a podcast, how to turn a podcast into clips; if it's a Twitch, Kick or YouTube stream, how to clip a stream.

Frequently asked questions

How long should a TikTok clip be?

As long as the story needs to make sense on its own, with no warm-up. In iaclips you choose Complete stories, up to 3 minutes, or Shorter, up to 90 seconds; shorter clips move faster but may feel a little less polished.

What size is a TikTok video?

Vertical 9:16, the shape that fills a phone screen. iaclips clips come out at 1080 × 1920 pixels. For its ads, TikTok recommends vertical 9:16 at a minimum of 540 × 960 pixels.

Can I make TikTok clips for free with no watermark?

Yes. In iaclips, the free plan includes 30 minutes of video every 30 days, with no watermark and no credit card, and every clip comes with captions. By hand it's free too: trim in your browser with our trimmer and add captions in CapCut.

How do I make several clips from one long video at once?

Paste the YouTube link or upload the video in iaclips: the AI finds every story that stands on its own and delivers each one as a vertical clip with captions. Download all gets you every clip in one step.

Should I use TikTok's captions or the clip's?

One or the other. iaclips clips already have captions burned into the video, so you don't need to add TikTok's own captions; if you do, the text shows up twice on screen.

How do I make TikTok clips from Twitch?

For one moment, Twitch's clip button makes clips up to 60 seconds with a portrait version you can post straight to TikTok. For longer clips, or many from a whole stream, download the VOD and upload it to iaclips. The details are in our guide on how to clip a stream.

Sources

Checked October 20, 2026 on each platform's own help pages. Button names can change with app updates.

Got a long video?

Paste the link or upload the file and get vertical clips with captions for TikTok. Free: 30 minutes every 30 days, no watermark.

What does a TikTok clip need?

How do I make TikTok clips with AI?

Paste a link or upload the video

Choose the length

Choose the caption look

Process and wait for the email

Check each clip's first sentence

Download and post to TikTok