// HOW-TO · SHORT-FORM

How to use X's updated video composer (2026)

X's updated video composer adds editable captions and Grok-powered caption correction and translation. Here's how to use it to post better video on X.

Last verified · 2026-10-05 · by Moe Ameen

In early October 2026 X rolled out an updated video composer — a cleaner, more focused layout for uploading and editing video, announced by X developer Allegra Jacchia. The headline change is captions: the composer now lets you edit the auto-generated transcript line by line, ask X's Grok assistant to correct it, and have Grok translate the captions into another language before you post. It builds on X's July 2026 video-editor overhaul, which added multi-language caption tools and green-screen recording, and the on-video overlays that followed.

This walkthrough covers the practical path through the new composer: getting your clip in, trimming it, using the caption tools that are the point of the update, and the placement and review checks that decide whether the video actually reads on a muted timeline. It also flags the one thing the composer does not solve — none of this polish travels when you post the same video anywhere else, so treat the composer as the X-native finish, not your whole video workflow.

The steps

Open the composer and add your video. Start a post and attach a video — record one in the app or upload a finished file. The updated composer opens into a dedicated video-editing layout rather than the old cramped attachment view, so the trim, caption, and overlay controls are surfaced instead of buried. Upload length is gated by account type: standard accounts are capped at a short clip, while Premium and Premium+ unlock much longer uploads, so check your tier before trimming to fit.
Trim and arrange the clip. Use the composer's trim handles to cut dead air off the front and back — the first second is what decides whether anyone stops scrolling, so lead with the hook, not a countdown or a logo sting. If you are stitching more than one clip, order them here. Keep the edit tight; X's timeline rewards a video that earns the view fast, and a long cold open is where most of the drop-off happens.
Record a green-screen segment or add overlays if the story needs them. Carried over from the July and August 2026 updates, the composer can record a green-screen segment (you in front of a replaced background — useful for reacting to a screenshot or article) and layer on-video overlays. These are optional; reach for them when they serve the point, not for decoration. Shoot vertical where you can, since most of X's video consumption is now on mobile.
Generate captions, then edit the transcript in the composer. This is the core of the update. X auto-generates captions from your audio, and the new composer lets you edit that transcript directly — line by line — instead of accepting whatever the transcription produced. Read every line and fix the three things auto-transcription reliably mangles: brand names, proper nouns, and numbers. A caption with your product name spelled wrong is worse than no caption at all, and now there is no excuse to leave it, because the edit is right there in the composer.
Ask Grok to correct and translate the captions. If the transcript is rough, you can hand it to X's Grok assistant to clean up rather than retyping it by hand. Grok can also translate the captions into another language, which is the composer's lever for reaching a non-English audience without a separate dubbing tool. Treat Grok's output as a draft: skim the corrected or translated lines before posting, since an AI pass still misreads names and idioms, and a confidently wrong translation is harder to catch than a garbled one.
Check placement and add post text and alt text. Confirm the captions sit in a readable band and are not clipped by X's playback controls or the reply bar on mobile — preview on a phone, not just the desktop composer. Then write the post text that frames the video (X still reads it for search and reach) and add alt text describing the video for accessibility. Captions on the video and the post copy are two different jobs; do both deliberately.
Post now or schedule it. When the clip, captions, and copy are right, post it — or schedule it for a peak window if you plan your timeline. Because the captions are baked into this specific X upload, they stay with the video on X, but they do not come along if you download the file and post it elsewhere. If this video is also going to Reels, TikTok, or Shorts, caption it for those platforms separately rather than assuming X's work carries over.

Common gotchas

Captioning is still a step you have to do — the composer makes editing captions easy, but it does not force it. Skip the caption pass and the video posts bare on a timeline most people watch muted.
Grok's caption correction and translation are a draft, not a final. It misreads brand names, numbers, and idioms; proofread before posting, especially a translation into a language you don't read.
The composer's captions and edits are X-native. Download the file to post on another platform and none of it travels — you re-caption for each destination.
Upload length depends on your account tier. A long cut that fits a Premium account will be rejected or truncated on a standard one — check the cap before you finish the edit.
Overlays and green-screen segments are easy to overuse. They help when they carry information; as decoration they just add noise and slow the hook.
Feature rollouts on X are staged and change fast. If a caption or Grok control isn't where this describes, it may not have reached your account or client yet — the layout and tools keep moving.

Where Kompozy fits

X's updated composer is a genuinely good native finish for a single X post — editable captions, a Grok cleanup, a translation pass, all in one view. The limit is baked into the last step of this guide: that polish lives on X and nowhere else. The same video going to Reels, TikTok, Shorts, and LinkedIn has to be re-trimmed and re-captioned in each app's own composer, by hand, every time. [Kompozy](/), a full AI content generation and multi-platform publishing engine, is for that other job — not replacing X's composer, but doing the cross-platform version of it so the per-app repetition disappears.

Here is the concrete difference. Instead of editing one clip for one timeline, you brief Kompozy once from a single [Persona Brief](/glossary/persona-brief) and it generates the video with captions already burned into the frame at render time — a [Persona Short](/glossary/persona-shorts) with an on-brand AI avatar, or a vertical cut clipped from long-form footage — styled from a caption preset and placed in the readable band, so the "did I remember to caption it" trap this tutorial keeps flagging cannot happen. The same source also fans out into formats X's composer will never make: brand-exact Carousel Posts built on [HyperFrames](/glossary/hyperframes), photo and quote posts, a blog article, and an email newsletter. Then [Autopilot](/glossary/autopilot) publishes the captioned, on-brand set natively across the eight social platforms plus blog and email — X included — from one queue behind a per-post review gate, where you catch a transcription slip before anything ships, the same proofread this guide asks you to do in the composer.

Honest boundary: for a one-off reaction clip you filmed on your phone and only want on X, X's composer is the faster path — use it, edit the captions, and post. Kompozy earns its place when that video needs to be captioned, on-brand, and live everywhere at once, repeatedly, which is exactly the work that quietly falls apart when every platform makes you do it by hand. Starter ($199/mo for 5,500 credits) fits a solo creator shipping a steady stream of captioned video across platforms; Pro ($499/mo for 18,000 credits) suits a brand or agency running many accounts and formats; Enterprise is custom.

Frequently asked questions

What is X's updated video composer?

It is a refreshed layout for uploading and editing video on X, rolled out in early October 2026. The main change is a focused editing view with an improved captioning process: you can edit the auto-generated caption transcript directly in the composer, ask X's Grok assistant to correct it, and have Grok translate the captions into another language. It builds on X's July 2026 video-editor update, which added multi-language caption tools and green-screen recording.

Can I edit captions on an X video now?

Yes. The updated composer lets you edit the auto-generated caption transcript line by line before you post, rather than accepting the raw transcription. You can fix the brand names, proper nouns, and numbers that auto-captioning most often gets wrong, or hand the transcript to Grok to clean up. Do the edit before posting — the captions are part of the upload.

Can Grok translate my X video captions?

Yes. The composer can pass your captions to Grok to translate into another language, which is X's built-in path to reaching a non-English audience without a separate dubbing tool. Review the translation before posting — an AI translation still misreads idioms and names, and a fluent-sounding but wrong line is easy to miss in a language you don't speak.

Does the X video composer work on web or only the mobile app?

X's video features roll out in stages and typically land on the mobile apps first, with availability varying by client and account. If a caption or Grok control described here isn't present for you, it may not have reached your platform or region yet. Check that your app is updated, and expect the exact layout to keep shifting as X iterates on video.

Do the composer edits transfer when I cross-post the video elsewhere?

No. The trims, overlays, and captions you create in X's composer are baked into that X upload only. If you download the file and post it to Instagram, TikTok, or YouTube, none of the X-native editing comes with it — you caption and edit again for each platform. That per-platform repetition is the real cost of relying on each app's native composer.