The short version: for most people, CapCut (free, desktop and mobile) is where you edit an AI generated video, because it handles the choppy cuts, mismatched audio and weird pacing that come out of tools like Runway, Sora, or Luma. If you’re editing for a client or need proper colour grading and multi-track audio, move up to DaVinci Resolve (free tier is capable) or Adobe Premiere Pro if you’re already in the Adobe ecosystem. The AI tool that generates your video is almost never the right place to finish it.
Why the generation tool isn’t the editing tool
I generated my first proper AI video clip in Runway back in early 2024, a 4-second shot of a coffee cup steaming on a desk for a client’s LinkedIn post. It looked lovely. It also had zero sound, ran 4 seconds when I needed 8, and didn’t match the brand’s other footage at all. I sat there for a good ten minutes trying to find an “edit” button inside Runway itself before I realised: there isn’t one, not a real one. These platforms are built to generate, not to finesse.
That’s the bit nobody tells you when you start playing with these tools. You watch a demo video where someone types a prompt and out pops a finished, polished ad, and you assume the tool does the whole job. It doesn’t. Sora, Runway, Pika, Luma, Kling, all of them give you raw footage. Sometimes brilliant raw footage. But raw all the same. The editing happens somewhere else, in a different piece of software, by a human who knows what they’re doing.
The free option: CapCut
CapCut is where I tell most small business owners to start, and it’s what I use myself for quick social clips. It’s free, it works on desktop and phone, and it was built with AI-generated and short-form content in mind from the start (it’s owned by ByteDance, same parent company as TikTok, so it’s optimised for exactly this kind of vertical, fast-cut content).
What it’s good at:
- Auto-captions that are accurate, better than YouTube’s native ones in my experience
- Stitching together multiple AI-generated clips into one sequence without needing to understand keyframes
- A built-in stock audio library so you’re not stuck with the flat, silent clip your generator gave you
- Speed ramping and simple colour matching, which matters a lot when you’ve generated five clips from five different prompts and they all look slightly different
What it’s not good at: anything that needs real precision. If you need frame-accurate cuts, proper audio mixing with multiple tracks, or colour grading that goes beyond a filter slider, you’ll hit CapCut’s ceiling fast. For a 15-second Instagram Reel, though, it’s more than enough, and it’s worth reading about why Instagram sometimes auto-writes odd descriptions for your Reels before you publish, because that’s a separate headache entirely.
The step up: DaVinci Resolve
When a client needs something that has to sit next to real filmed footage, I move to DaVinci Resolve. It’s made by Blackmagic Design, the same company that makes cinema cameras, and the free version has no watermark and does about 90% of what the £254-a-year Studio version does.
Here’s a real workflow I used last month for a fintech client who wanted a 30-second explainer built from four AI-generated background clips plus a voiceover:
- Generated the four scene clips in Runway Gen-3, each 5 to 8 seconds, at 1080p
- Imported all four into DaVinci Resolve’s Edit page and laid them on the timeline in sequence
- Used the Colour page to match white balance across all four, because two of them had come out noticeably warmer than the others (this is common, AI generators don’t guarantee consistency between separate prompts)
- Recorded the voiceover separately in Audacity (free) and dropped it into a second audio track
- Added a third track for a licensed music bed at 15% volume so it sat under the voice without fighting it
- Used Fusion (Resolve’s built-in compositing tool) to add a simple text overlay for the company name, since AI generators still can’t reliably render clean, legible text inside a video
- Exported at 1080p, 24fps, H.264
Total time: about 3 hours, most of it the colour matching. That’s the unglamorous truth about editing AI video: the generation takes two minutes, the editing takes hours, and the colour and audio matching is where most of that time goes.
Adobe Premiere Pro, if you’re already paying for it
If your business already has an Adobe Creative Cloud subscription (around £54.99 a month for the full suite, or £23.99 a month for Premiere alone in the UK), stay there rather than learning a new tool. Premiere’s Lumetri colour panel does the same job as Resolve’s colour page, and if you’re also doing thumbnail work or graphics in Photoshop or Illustrator, the file handoff between apps is smoother. Premiere also has a useful feature for AI clips specifically: Enhance Speech, which cleans up the flat, slightly robotic audio that comes out of AI voice tools before you even touch the video track.
The trade-off is cost and a steeper learning curve. If you’re a solo business owner doing this once a month, Premiere is overkill. If you’re producing video weekly, it earns its subscription.
Mobile-only options if you’re not touching a laptop
Not everyone wants to sit at a desk to finish a 20-second clip. CapCut’s mobile app covers most of the same ground as desktop. InShot is a decent alternative if you find CapCut’s interface cluttered, it’s simpler but has fewer AI-assisted features. Both let you trim, add captions, layer music and export straight to Instagram or TikTok without ever opening a laptop, which matters if you’re generating and posting on the move, something I do a fair bit when I’m between client meetings.
The uncomfortable bit: most AI video still needs more editing than people budget for
Here’s the part that gets skipped in a lot of the “top 10 AI video tools” content out there: the marketing around these platforms implies you’ll go from prompt to finished, publishable video in minutes. For a single 6-second clip with no dialogue, maybe. For anything with a message, a brand, or a client attached to it, you’re looking at real editing time, real skill, and often a second or third tool.
I’ve had prospective clients come to me expecting to spend £50 on an AI video subscription and walk away with a month of finished ad content. What happens is they generate 20 clips, half of them unusable because of warped hands, flickering backgrounds or text that renders as gibberish, and then they need someone who knows an editing tool to stitch the usable ones into something coherent. The generation cost is cheap. The editing time is where the real cost sits, whether that’s your own hours or a freelancer’s.
That’s not a reason to avoid the tools. It’s a reason to budget for editing time from the start rather than treating it as an afterthought once the “AI video” turns out to look like exactly what it is: a series of disconnected clips.
Matching the tool to the platform you’re generating for
Which editor you need also depends on which generator you used and what you’re building. If you’re comparing which AI video generator suits business marketing in the first place, know that some produce footage that’s easier to edit than others. Runway and Luma tend to output clean MP4s that drop straight into any editor. Sora clips sometimes need re-encoding before Premiere will read them, a small but annoying extra step. If you’re building something more structured, like generative AI video for a business use case such as onboarding or product demos, you’ll spend more time in the editor adding text, logos and calls to action than you spent generating the base footage.
It’s also worth knowing the scale of the market you’re picking from. There are now well over 60 distinct AI video generator tools in active use, and new ones launch most months, but the editing layer hasn’t kept pace. Nearly all of them assume you’ll finish the job somewhere else.
What I recommend, by budget
- £0 budget, occasional social clips: CapCut, desktop or mobile
- £0 to £20/month, need it to look professional: DaVinci Resolve free tier
- Already paying for Adobe, or need heavy graphics work too: Premiere Pro
- No time or skill to edit at all: hire it out. A freelance video editor on a platform like Upwork typically charges £15 to £40 an hour for this kind of assembly work, and a 30-second polished clip usually takes 2 to 4 hours once you include the AI footage cleanup
If AI video is becoming a bigger part of your content plan and you’re not sure whether to build the skill in-house or bring in help, that’s exactly the kind of decision worth talking through, and it’s the sort of thing I cover with clients through AI implementation coaching, because the tool choice matters far less than the workflow around it.
One last practical note: whatever you edit in, keep your raw AI clips. I’ve had a client ask for a “quick tweak” three weeks after delivery, and if you’ve only saved the final export, you’re regenerating from scratch. Save the source files the same way you would with any other video production project, because AI generation isn’t cheap enough yet, in time or in credits, to redo casually.
I covered the follow-on problem in Your AI Meeting Notes Are Making You Look Worse, Not Better.
Frequently asked questions
Can I edit an AI generated video for free?
Yes. CapCut and DaVinci Resolve both have fully functional free versions with no watermark, and either one can take a raw AI clip through cutting, colour matching, captions and audio in under an hour for a short social video.
Why does my AI video need editing if the AI already generated it?
AI video generators produce individual clips, usually 4 to 10 seconds long, with no audio, inconsistent colour between separate generations, and no branding. Editing is where you stitch those clips together, add sound and text, and make them look like one coherent video rather than a set of disconnected samples.
What’s the best free tool to edit AI video on a phone?
CapCut’s mobile app is the strongest free option for phone-only editing, with accurate auto-captions and an audio library built in. InShot is a simpler backup if you find CapCut’s interface too busy.
Should I edit inside the same tool that generated the video, like Runway or Sora?
No. These platforms are built for generation, not editing, so they lack multi-clip timelines, proper audio mixing and colour tools. Export the raw clip and finish it in a dedicated editor like CapCut, DaVinci Resolve, or Premiere Pro.
