TikTok Ads vs Instagram Reels Ads: Which Is Right for Your Business?

Deciding where to put a short-form video budget is one of the most common questions our team hears from UK business owners and marketing managers. It is easy to get pulled towards whichever platform happens to dominate marketing headlines that month. Both channels put vertical video front and centre, both rely heavily on machine learning to find buyers, and both can either scale sales quickly or burn through budget if set up carelessly. The smarter choice comes down to who you sell to, how your product looks on camera and how regularly you can produce fresh video creative.

The short answer

Neither platform wins across the board, because TikTok and Instagram Reels reward different types of creative and buying behaviour. TikTok tends to shine when you can produce regular, natural-looking videos that entertain or demonstrate a product quickly, while Instagram Reels benefits from Meta’s mature ecommerce tools and broad cross-placement reach. The table below summarises how the two compare for UK advertisers.

Who you’ll reach on each platform

Understanding UK reach starts with separating perception from actual usage. According to Ofcom’s Online Nation 2025 report, Instagram reaches 78% of UK online adults each month, while TikTok reaches 56% after growing 14% in a year. Many SME owners still assume TikTok is strictly for teenagers and students, but a platform used by more than half of UK online adults clearly reaches well beyond them.

Rather than asking whether your customers exist on one platform or the other, ask how they behave while scrolling each feed. The same person might browse TikTok for entertainment and product discovery in the evening, then use Instagram to check out a local business they have heard about.

How the ad formats compare

Although both platforms deliver full-screen vertical video, the way you buy and structure placements differs. Running structured TikTok ad campaigns gives you access to three main formats:

• In-Feed Ads: Full-screen videos that appear in a user’s “For You” feed as they scroll, with a call-to-action button leading to your website or TikTok Shop.
• Spark Ads: Paid budget behind an existing organic post from your own profile or an authorised creator’s account, keeping all likes, comments and shares attached to the original video.
• TopView Ads: High-impact placements that appear when a user opens the app, usually suited to larger brand launches rather than everyday SME budgets.

By contrast, Instagram Reels ads sit between organic Reels in the Reels tab and main feed. The biggest structural difference is that Meta rarely isolates Reels unless you tell it to. Within a single Meta campaign, your vertical video can run across Instagram Reels, Stories, the main Instagram Feed and Facebook advertising placements, with Meta’s delivery system placing each impression wherever results are cheapest.

What about YouTube Shorts? Once you have a repeatable workflow for filming vertical video, testing YouTube Shorts ads alongside TikTok and Meta is an easy way to reach people who spend more time on YouTube than on social apps.

Creative that works on each

On both platforms, your video creative does far more heavy lifting than your audience settings. Algorithms now use visual signals, spoken audio and on-screen text to decide who should see your ad, so weak creative gets penalised with higher costs however carefully you configure your campaign.

TikTok is a sound-on environment where polished corporate adverts stand out for the wrong reasons. Videos that feel native to the platform, such as a founder explaining a common problem to camera, an unboxing clip or a quick before-and-after demonstration, tend to outperform studio-lit brand films. Winning attention in the first two seconds matters on both feeds, and strong short-form video hooks stop viewers swiping past before your offer lands.

Instagram Reels also rewards authentic, creator-style content, but users tend to accept cleaner typography and slightly more considered brand aesthetics. On both platforms, some people watch without sound, so clear on-screen captions are worth adding as standard. Working with creators on user-generated content (UGC, meaning videos filmed by real customers or creators rather than a production crew), or commissioning bespoke short-form ad creative, helps your videos match each platform’s rhythm while keeping key text clear of each app’s on-screen buttons and captions.

Targeting and automation

Both platforms have spent the past two years moving advertisers away from granular manual targeting towards AI-driven campaign setups. On TikTok, Smart+ campaigns automate audience targeting, bidding and creative combinations from a single setup, and TikTok has now extended Smart+ to TikTok Search Ads as well. On Meta, Advantage+ campaigns play a similar role, combining prospecting and remarketing into one machine-learning-led structure.

In practice, you hand over control of narrow interest stacks, age splits and placement bids to the algorithm. What you keep control of are your budget caps, geographic boundaries, conversion objective and, most importantly, the variety of creative you feed into the system.

One detail worth checking in Meta Ads Manager is which AI creative enhancements are switched on. Meta can apply enhancements such as adding music, adjusting visuals or generating text variations on your uploaded ads. Preview every placement and switch off any enhancements that clash with your brand guidelines or cover important product details.

Costs and budgets

When clients ask how much TikTok ads or Instagram Reels ads cost, they usually want a neat average CPM (cost per thousand impressions) or CPC (cost per click). In reality, published averages tell you very little, because auction prices swing widely depending on your sector, time of year, audience and how strongly viewers engage with your video. Seasonal peaks such as Black Friday and Christmas push competition up on both platforms at once.

Instead of chasing benchmark figures, plan your spend around giving the algorithm enough conversion data to learn. Both TikTok and Meta need a steady stream of conversion events, such as purchases or completed enquiry forms, to exit their initial learning phase and stabilise delivery. Spreading a small budget thinly across several campaigns or ad sets starves both platforms of the signals they need.

As a rule of thumb, TikTok’s own guidance is to set each ad group’s daily budget at around ten times your target cost per acquisition. TikTok treats roughly 50 conversions as the main sign an ad group has left its learning phase, and Meta looks for around 50 results within a week. If your budget can’t support that on two channels at once, start on one platform rather than splitting spend too thin.

Shopping and search features

Short-form video platforms are no longer purely discovery channels. Both now blend entertainment with shopping and search intent. TikTok Shop lets UK brands tag products in video ads so customers can browse and check out without leaving the app, and TikTok says more than 300,000 UK small businesses were selling through it by July 2026. TikTok Search Ads let advertisers bid on keywords when users look up reviews, tutorials or recommendations, reflecting how many people now use TikTok as a search engine. In its Q4 2026 product update, TikTok also announced impression share metrics for Search Ads, showing how often your ads appear for the keywords you target.

Meta continues to build around its established product catalogue rather than pushing every retailer into in-app checkout. Retailers can sync their product feeds to run dynamic product ads in Reels, and in October 2026 Meta told some advertisers it would switch on product browsing in their existing ads, letting viewers explore related items from a video ad. Meta has also started gradually rolling out video ads in Instagram search results, creating another high-intent placement for brands already producing vertical video.

Measuring results fairly

Comparing TikTok and Instagram results side by side in their own dashboards is one of the fastest ways to make poor budget decisions. Both platforms rely on a browser pixel (a snippet of tracking code on your website) and a server-side connection (Conversions API on Meta, Events API on TikTok) that sends purchase and lead data directly from your server to recover conversions lost to browser restrictions.

Even with tracking set up properly, platform-reported numbers can’t be compared like for like. Each platform uses its own attribution windows (for example, claiming a sale within seven days of a click or one day of viewing an ad), so TikTok and Meta can both claim credit for the same customer. Meta has also told advertisers that from 12 November 2026 its Pixel counts some conversions measured on customers’ devices, with the setting switched on by default, which can lift reported conversions compared with earlier periods.

To keep measurement honest, cross-check platform dashboards against Google Analytics 4 (GA4), your ecommerce platform or your CRM, and consider adding a simple “Where did you first hear about us?” field to checkout or enquiry forms. Make sure every ad clicks through to fast, focused mobile landing pages, because a slow page will hurt conversion rates whichever platform sent the click.

Which should you choose?

If you are still deciding where your first pound of spend should go, match your business to the scenarios below.

A local service business

Start with Instagram Reels inside a broader Meta campaign. Meta’s radius targeting, combined with Facebook placements, makes it easier for clinics, trades, gyms and hospitality venues to reach local adults without wasting impressions across the rest of the UK.

A fashion or beauty ecommerce brand

Test both, starting with whichever matches your creative strengths. Visual, wearable and demonstrable products often thrive on TikTok through creators and TikTok Shop, while Instagram Reels pairs well with catalogue retargeting to convert browsers who need a few touchpoints before buying.

A B2B company

For most B2B companies, LinkedIn advertising will be a stronger starting point than either of these platforms, because you can target by job title, industry and company size. If you are choosing between TikTok and Instagram specifically, start with Meta. Decision-makers use Instagram and Facebook outside working hours, and Meta’s lead forms and website remarketing make it simpler to capture and nurture enquiries.

A brand selling to under-25s

Start with TikTok. Young adults use both platforms, but TikTok’s creator-led, entertainment-first format suits how this audience discovers new brands, especially when campaigns use Spark Ads with relatable creators.

A business with little video content

Start with Meta, running Instagram Reels alongside Feed and Stories. Meta lets you test carousels, simple motion graphics and lightly edited vertical clips alongside static ads while you build a library of stronger native video.

How to test both without wasting budget

If your audience sits comfortably across both platforms and you want real data from your own customers, run a structured head-to-head test as part of your wider paid social strategy. Follow five simple rules so the test stays fair:

1. Keep the offer identical: Promote the same product, bundle or lead magnet on both platforms so price or promotion differences don’t skew the result.
2. Match your creative angles: Film two or three distinct hooks around the same core message, adapting captions and pacing to suit each feed without changing the underlying proposition.
3. Split budgets equally: Give both platforms the same daily spend, making sure each has enough to gather meaningful click and conversion volume.
4. Run a fixed test window: Run both campaigns uninterrupted for at least four to six weeks so both algorithms have time to exit their learning phase and settle.
5. Judge on one primary metric: Agree upfront whether you are measuring cost per acquisition (CPA), return on ad spend (ROAS) or qualified leads, and judge both channels on your own backend numbers rather than engagement metrics.

If you would like practical advice on where to put your short-form video budget next, speak with our paid social team and we will help you map out a clear test plan.