How to Edit a Video with AI: A Step-by-Step Guide

Decide what the finished video is before you open an editor. Write down five things: who it’s for, where it will be posted, roughly how long it should be, what must stay, and what should go. That paragraph becomes your first prompt, and it’s also how you’ll judge the result.

Example: a product walkthrough for new customers on YouTube, 6–8 minutes in 16:9. Keep the setup and all three features; cut the dead air, the restarts and the failed page load; clean captions and my uploaded music low under my voice. More starting points are in the prompt library, and how to write AI video editing prompts shows before-and-after rewrites.

Upload the original recording, not a compressed re-export. Valmera takes MP4, MOV, M4V, MKV and WebM files up to 14 GB and 3 hours each, plus images (PNG, JPG, WebP) and music (MP3, WAV, M4A, AAC, OGG) up to 50 MB. Add your logo, music and b-roll clips now, or paste links in the chat later.

Once the upload finishes, Valmera indexes the video: a word-level transcript with speaker labels, shot changes, silences, on-screen text and a lightweight proxy for fast previews. That index is why you can say “cut the part where I mention pricing” instead of hunting for timestamps. Details: uploads and word-level timestamps.

This is where AI saves the most time, so ask for all three cleanup passes at once. Cuts land on word boundaries, so no syllable gets clipped, and every cut is non-destructive: your original file is never modified and anything removed can be restored.

Check: listen across a few joins. If one feels rushed, say where: “loosen the cut at 2:14.”

Go deeper: remove silence, remove filler words, remove repeated takes.

Captions are timed word by word from the transcript and burned into the picture. Choose a style by name (clean, karaoke, podcast, beast, elegant and more), plus position, size and words per line. Correct a misheard word once and it’s fixed everywhere.

Check: names, numbers and jargon, and that captions don’t cover faces or on-screen text.

Go deeper: add captions to video, karaoke captions, caption styles.

Use 9:16 for TikTok, Reels and Shorts, 1:1 or 4:5 for feeds, and 16:9 for YouTube. Auto reframe finds the subject and aims the crop at them. Footage that runs to the edges, like a screen recording, is fitted over a blurred background instead of cropped, and captions rescale to the new frame.

Check: gestures, people near the edges, and any text that has to stay readable.

Go deeper: auto reframe, resize video for any platform, editing for TikTok.

B-roll: the agent finds stock footage and real photos that match what you’re saying and lays them over your voice, or uses clips you upload. Music: bring your own track, paste a link, or name a song; the agent mixes it under speech with smooth ducking and can snap cuts to the beat. Sound effects are real recordings found on the web, like a whoosh, a click or a camera shutter, placed on an exact moment. Finish with loudness mastering so the video isn’t quiet on phones.

Check: the b-roll matches the words, the music never fights the voice, and you have the rights to any music you bring.

Go deeper: add b-roll, add music, add sound effects, beat sync.

Before it replies, Valmera renders a preview and inspects its own frames and audio, so problems like a caption over a face usually get fixed before you see them. Watch the whole preview anyway. Then revise in plain English: name the problem, where it is, and what to keep.

Every revision is saved as a new version. Use Previous edit in Studio to step back, or adjust the timeline and transcript by hand when that’s faster.

Export renders a full-resolution H.264 MP4 from your original file, not from the preview proxy. Paid exports end with a brief Valmera end card. Download the MP4, watch it once more, and post it yourself. Captions are already burned in, so there’s no subtitle file to upload. See export and delivery.

Or do the whole edit in one message

Once you know what you want, one prompt can cover the whole edit. The agent orders the dependent steps itself: cuts first, then captions timed to the new cut, then framing and the mix.

Splitting the same work into rounds, structure first and style second, makes each preview easier to judge.

Try the Steps on Your Own Footage

Creating an account and uploading are free. Editing requires a subscription.

Which kind of AI tool should you use?

“AI video editor” covers four different kinds of tools. Choose by what you start with and what you want back. Plenty of projects use two: generate one shot you couldn’t film, then edit it into your real footage.

• Agentic editors. Valmera works from a brief on footage you upload. Descript describes its Underlord assistant as an agentic co-editor inside Descript’s text-based editor, a natural fit if your team already edits there.
• Timeline editors with AI features. Premiere lists Text-Based Editing, Media Intelligence search, Enhance Speech, Object Mask and Generative Extend. DaVinci Resolve has a free version, and Resolve Studio adds neural tools such as Magic Mask and Voice Isolation. CapCut’s browser editor pairs a drag-and-drop timeline with auto subtitles and background removal.
• Clip generators. OpusClip turns long videos into short clips with AI reframing, captions and one-click publishing.
• Text-to-video generators. Runway’s Gen-4.5 model generates new video, and its creative suite also edits video, images and audio.

Product details checked October 6, 2026 on each company’s site: Descript Underlord, Adobe Premiere, DaVinci Resolve, CapCut online editor, OpusClip, Runway. For a shortlist, see the best AI video editors; for the difference between editing and generating, see AI video editor vs generator.

Edit with Claude or ChatGPT instead

Valmera also runs as an MCP server, so Claude, ChatGPT, Cursor and other MCP clients can do every step above with Valmera’s tools. Connect https://valmera.io/mcp/server, then upload, edit, review the preview and export the final MP4 without leaving the chat. The assistant drives the tools itself rather than handing the job to Valmera’s in-house agent. Setup guides: Claude, ChatGPT, and the MCP overview.

Limits to know before you start

• Valmera edits footage you provide; it doesn’t generate video from text.
• Captions are burned into the video. There’s no SRT or VTT import or export.
• There’s no audio denoise (“studio sound”) and no AI music generation, so record clean audio and bring your own music.
• No true crossfades or dissolves, no custom font uploads, and no motion-tracked stickers.
• No direct publishing to YouTube or TikTok, and no team seats yet.
• English is the best-tested transcription language.

Frequently Asked Questions

Made with Valmera: real exports

Edit Your Next Video by Describing It

Upload your footage, paste a prompt from this guide, and review the preview. Creating an account and uploading are free; editing requires a subscription.