Rightmove vs OnTheMarket United Kingdom | GPPI Independent Comparison
Quick Verdict
CoStar Group's £99M acquisition of OnTheMarket in early 2024 — followed immediately by a commitment of approximately £45–47M per year in UK sales and marketing — is the most significant structural event in the UK property portal market since Rightmove's FTSE 100 ascent. It reframes the OnTheMarket question from 'niche challenger' to 'CoStar-funded portal with the deepest parent-company balance sheet in global commercial real estate.' That said, the comparison between Rightmove and OnTheMarket in 2026 is not yet close. Rightmove's 77 million monthly users (company source data), £389.9M FY2024 revenue, and approximately 70% underlying operating margin represent a platform that has been built into consumer infrastructure over 24 years. Its ARPA of approximately £1,524 per month and the near-universal industry assessment that Rightmove is non-negotiable for UK estate agents reflect a position that CoStar's investment — however large — cannot replicate through marketing spend alone in a 12–24 month window. OnTheMarket's value proposition has shifted dramatically post-acquisition. Under pre-CoStar management, OTM differentiated on the 'Only With Us' exclusivity model — requiring agents to list on OTM before other portals — a position that constrained adoption. CoStar has relaxed this requirement and is deploying capital to build a portal that competes on audience reach rather than exclusivity. The approximately 14,000 agent branches on OnTheMarket represent a starting base; CoStar's stated goal is to build a portal competitive with Zoopla before taking on Rightmove directly. For agents making practical subscription decisions in 2026, Rightmove remains non-negotiable. The question is whether OnTheMarket — powered by CoStar's capital and data assets — merits a supplementary subscription slot ahead of, or alongside, Zoopla. The answer depends on whether CoStar's consumer traffic investment is translating into measurable buyer and renter inquiry volumes that justify the OnTheMarket cost line. The evidence will emerge over 2026–2027. Use Rightmove as the mandatory primary portal. Evaluate OnTheMarket as a supplementary portal on cost-per-completed-instruction metrics, not on traffic rank.
GPPI Pillar Scorecard
Side-by-side assessment across the four GPPI benchmark dimensions. GPPI scores are assessed from public signals. They are not derived from portal subscriptions or commercial relationships. Methodology: GPPI v2.1.
| Pillar | Rightmove | OnTheMarket | Leader |
|---|---|---|---|
| Listing Quality | Rightmove: approximately 980,000 active listings across residential sale, lettings, new homes and commercial; 4.8-star app rating reflects consumer trust; EPC integration, Homeviews neighbourhood reviews, and 99.99% uptime in FY2024 signal a high-reliability listing environment. | OnTheMarket: approximately 14,000 agent branches as of source data; listing count not publicly disclosed; CoStar's commercial property data assets could enhance listing quality signals in commercial categories; the portal is in a growth phase adding agent coverage, meaning listing completeness is improving but not yet at Rightmove or Zoopla levels. | Rightmove |
| Discoverability | Rightmove: 77 million monthly users per company data; ranked number one in the UK Real Estate category by Similarweb; direct-navigation dominance reflects deep consumer habit; 4.8-star app rating supports strong app store discoverability and retention. | OnTheMarket: consumer audience in active build phase; CoStar's £45–47M annual UK marketing spend is explicitly directed at audience growth; traffic figure not publicly disclosed as a stable audited metric; the portal is investing in brand awareness campaigns targeting both consumers and agents. | Rightmove |
| Market Experience | Rightmove: consumer journey spans search, MyPlaces saved properties, local valuation alerts, mortgage calculator, renovation cost tools, EPC data, Homeviews neighbourhood reviews, and Lead to Keys tenancy management; 5,000+ product releases in FY2024 reflect sustained investment in journey completeness. | OnTheMarket: property search with filters, saved searches and alerts, agent profiles, new homes section; the consumer product is less feature-rich than Rightmove in its current form, reflecting CoStar's focus on audience-building and agent coverage expansion rather than consumer feature depth in the immediate post-acquisition phase. | Rightmove |
| Product Innovation | Rightmove: 5,000+ product releases in FY2024; 3.0 petabyte data platform on GKE with Kafka and Elasticsearch; named innovation includes Optimiser Edge, Local Valuation Alert, Discover, Renovation Calculator, EPC integration, Homeviews, and the full Rightmove Plus suite. | OnTheMarket: CoStar is a global leader in commercial real estate data and analytics; the integration of CoStar's technology assets into a UK residential consumer portal is a multi-year product development project; the potential for CoStar's data infrastructure to power differentiated UK property search and valuation products is high but largely unrealised in the consumer product as of 2026. | Rightmove |
Listing Quality
Rightmove's 980,000-listing pool and 4.8-star consumer trust rating give it a decisive listing quality and volume advantage over OnTheMarket in 2026. OnTheMarket's listing quality trajectory is improving under CoStar investment, but the volume and trust gap is material.
Discoverability
Rightmove's discoverability advantage is structural and deep-rooted: 77 million monthly users built on 24 years of consumer habit formation cannot be closed by marketing spend in a 12-month window. OnTheMarket's CoStar-funded brand investment is closing the gap directionally, but Rightmove leads decisively in 2026.
Market Experience
Rightmove's consumer product is materially more feature-complete than OnTheMarket's current offering. OnTheMarket's market experience is functional and improving, but has not yet received the same depth of product investment as Rightmove's 5,000+ annual release cadence.
Product Innovation
Rightmove leads on current delivered product innovation — 5,000+ releases per year with a named pipeline. CoStar's data and technology assets could potentially power superior product innovation in future years, but the realised UK residential product innovation is at an earlier stage in 2026 than Rightmove's current position.
Strategic verdict: Rightmove vs OnTheMarket in the UK
This comparison is best understood as two separate questions with different time horizons. In 2026, the question is simple: Rightmove is the non-negotiable primary portal for UK agents, and OnTheMarket is an early-stage challenger backed by the deepest capital commitment in UK portal history. The strategic question with a longer horizon is different: can CoStar — one of the world's largest commercial real estate data and analytics companies, with a market capitalisation of several billion dollars — build a UK residential property portal that eventually challenges Rightmove's consumer position? The answer to the second question is genuinely unknown, and the £45–47M per year UK marketing investment is the most serious attempt to find out. Rightmove's position is built on a self-reinforcing network that has compounded for 24 years: more listings attract more consumers, more consumers attract more agent subscribers, more agent revenue funds more product investment, better product retains more consumers. This loop is structurally difficult to break from the outside. CoStar's thesis is that sustained capital deployment — building consumer brand awareness faster than organic growth alone — can disrupt the habit formation loop enough to give agents a credible alternative. The pre-CoStar OnTheMarket built a reputation on the 'Only With Us' exclusivity model, which constrained adoption by requiring agents to prioritise OTM listings before other portals. CoStar has relaxed this requirement and is building a conventional portal growth strategy: invest in consumer brand, expand agent coverage, improve product, repeat. For agents making subscription decisions in 2026, the practical guidance is clear: Rightmove first, always. The OnTheMarket supplementary question should be evaluated alongside the Zoopla supplementary question on the same metric: cost per completed instruction from each portal's leads. The agent who can demonstrate that OnTheMarket's CoStar-funded traffic growth is delivering measurable instruction volume at a competitive cost per instruction has a rational basis for a supplementary OTM subscription. Those who cannot should wait for more evidence of OnTheMarket's consumer build before committing their supplementary budget.
Where Rightmove has a structural edge
Rightmove's structural edge is not primarily about product features or marketing spend — it is about the depth of consumer habit formation that 24 years of market-leading position has created. A significant share of UK property searchers navigate directly to Rightmove.co.uk without a Google search intermediary, reflecting the same kind of direct-navigation dominance that Google itself enjoys for web search. This direct traffic is not replicated through advertising; it is built through years of being the platform consumers think of first, and it constitutes a moat that marketing spend alone cannot break. The commercial dimension of Rightmove's structural edge is equally important. An ARPA of approximately £1,524 per month in FY2024 — with 5,706 member agencies paying this — reflects pricing power that only a near-mandatory platform can command. Rightmove's ability to raise prices annually (ARPA growth from approximately £1,308/month in 2023 to £1,524/month in 2024) without triggering mass agent churn is the most visible expression of its structural position. The product dimension is the third leg of Rightmove's advantage: 5,000+ product releases in FY2024 on a 3.0 petabyte data platform with Kafka, Elasticsearch, and GKE microservices represents a product velocity that a portal in its first two years under new ownership cannot match. Named products including Optimiser Edge, Local Valuation Alert, Discover, the Renovation Calculator, EPC tools, Homeviews, Lead to Keys, and the full Rightmove Plus suite represent a deep feature surface that has been built and refined over years of agent and consumer feedback.
Where OnTheMarket changes the equation
OnTheMarket's most important differentiator is not what it has built yet — it is the magnitude of the capital backing it. CoStar Group is a NASDAQ-listed company with a multi-billion dollar market capitalisation built on commercial real estate data dominance in the United States. Its commitment of approximately £45–47M per year in UK residential portal marketing is not a startup bet; it is a strategic allocation from an established data business that has demonstrated the ability to build leading market positions in commercial real estate information markets globally. For UK agents assessing whether OnTheMarket will matter in 2028 or 2030, CoStar's capital commitment is the most relevant signal — not OnTheMarket's current traffic figures. The second meaningful differentiator is CoStar's commercial real estate data depth. CoStar's LoopNet portal and CoStar data platforms are the dominant information sources for commercial property in the United States. The potential integration of these data assets into a UK commercial and new-homes search capability could give OnTheMarket a structural advantage in the commercial property category that Rightmove — historically a residential-origin portal — does not currently match. If CoStar builds a superior commercial and new-homes search experience on OnTheMarket and bundles it with competitive residential coverage, the value proposition for mixed-portfolio agencies (residential and commercial) could become compelling. The third differentiator is CoStar's willingness to absorb short-term losses to build long-term market position — a capital structure that listed Rightmove, under analyst scrutiny, cannot replicate by choice.
When to choose Rightmove, when to choose OnTheMarket, and when to use both
The decision framework for UK agents evaluating Rightmove and OnTheMarket is relatively clear in 2026, though it will need revisiting as CoStar's investment matures. Rightmove is non-negotiable as a primary portal: its 77 million monthly users, near-universal agent base, and near-mandatory status in agent inquiry economics mean that withdrawing from Rightmove is commercially self-defeating for virtually all UK estate and letting agents. The supplementary portal question — whether to use OnTheMarket alongside Rightmove, or Zoopla, or both — is where the decision becomes genuinely analytical. Choose OnTheMarket as your supplementary portal if you are an agent with commercial or mixed-portfolio properties in your stock, where CoStar's commercial data depth might translate into stronger search visibility. Also consider OnTheMarket if you have been offered a competitive introductory rate by CoStar's UK sales team during the portfolio-building phase — these rates may not persist once CoStar achieves its audience targets. Evaluate Zoopla as an alternative supplementary portal if your strategy prioritises seller lead generation (via Prospect Plus) or if your agency uses Alto or Jupix CRM. Use both Zoopla and OnTheMarket if your volume justifies the combined subscription cost and if you can measure cost per completed instruction from each independently — the test metric that matters, not cost per lead or traffic rank. The agent who evaluates supplementary portals on cost per completed instruction will make the right call; the agent who chooses on brand recognition or traffic headlines may overpay for reach that doesn't convert.
GPPI pillar implications for Rightmove vs OnTheMarket
Across all four GPPI pillars — listing quality, discoverability, market experience, and product innovation — Rightmove leads in 2026. The exception is the parent-company financial firepower dimension, where OnTheMarket's CoStar backing represents the single most important factor determining whether this comparison looks fundamentally different in 2028. On listing quality, Rightmove's 980,000-listing pool and 4.8-star consumer trust score dwarf OnTheMarket's current coverage. Buyers and renters who search only OnTheMarket will miss significant inventory; this listing gap is the most concrete near-term barrier to OnTheMarket achieving supplementary portal status for buyers. CoStar's agent coverage investment is designed to close this gap, but it requires agents to actively add OTM listings, which requires convincing agents that OTM's consumer traffic justifies the additional admin. On discoverability, Rightmove's 77 million monthly consumer habit is not replicated through advertising — it requires years of being the platform consumers think of first. CoStar can buy impressions; it cannot buy the direct-navigation habit that Rightmove has built. On market experience, Rightmove's 5,000+ annual releases give it a consumer product depth that OnTheMarket's post-acquisition rebuild is still closing. On product innovation, CoStar's data assets represent a latent advantage that has not yet been realised in the UK residential consumer product. The GPPI scorecard supports a clear hierarchy in 2026: Rightmove is the only mandatory portal, and OnTheMarket is an early-stage supplementary option that merits evaluation on cost-per-instruction metrics rather than traffic comparisons. The picture in 2028 depends entirely on whether CoStar's capital deployment translates into consumer habit and agent coverage — a question that cannot be answered today.
Who Leads Where
Independent GPPI dimension-by-dimension assessment. Methodology: GPPI Methodology
Consumer audience scale
Rightmove's 77 million monthly users (company data) versus OnTheMarket's undisclosed but materially smaller audience represents a structural gap that CoStar's £45–47M annual UK marketing spend is explicitly designed to close over multiple years, not overnight. Rightmove's consumer franchise was built over 24 years of network effect compounding.
Revenue and commercial scale
Rightmove reported £389.9M in FY2024 revenue at approximately 70% underlying operating margin, versus OnTheMarket's undisclosed post-acquisition revenue (OTM was reporting approximately £34M in annual revenue prior to the CoStar acquisition in 2024). The financial asymmetry is structural; CoStar's capital deployment is an investment into future scale, not current scale.
Parent-company financial firepower
CoStar Group (NASDAQ: CSGP), OnTheMarket's parent, is a multi-billion dollar US-listed commercial real estate data business with the balance sheet to sustain £45–47M per year in UK marketing spend indefinitely while absorbing losses. Rightmove, as a profitable FTSE 100 public company, does not have an equivalent unlimited capital backer — and while it does not need one, the asymmetry means CoStar can out-spend Rightmove on consumer marketing without constraint.
Product innovation and data assets
Rightmove's 5,000+ product releases in FY2024 on a 3.0 petabyte GKE data platform demonstrate sustained product velocity. Named products including Optimiser Edge, Local Valuation Alert, Discover, the Renovation Calculator, EPC tools, Homeviews, and the Rightmove Plus suite represent a deep feature surface. CoStar brings substantial US commercial data assets but the translation of these into UK residential consumer products is in progress rather than complete.
Agent listing mandate
UK agents consistently describe Rightmove as the portal they cannot leave without losing material inquiry volume. OnTheMarket, while growing under CoStar's investment, is not yet described in the same mandatory terms by the majority of UK agents. The approximately 14,000 agent branches on OTM represent meaningful but incomplete coverage relative to Rightmove's near-universal agent base.
New homes and commercial data capability
CoStar's commercial real estate data capabilities — including its LoopNet commercial property portal and CoStar data platforms — provide OnTheMarket's parent with a structural advantage in commercial and new-homes data depth that Rightmove's purely residential-origin portal architecture does not match. If CoStar integrates its commercial data assets into OnTheMarket's UK product, it could create a differentiated proposition for commercial and new-homes advertisers.
Frequently Asked Questions
- Is Rightmove or OnTheMarket better for UK property agents in 2026?
- Rightmove is the non-negotiable primary portal for the overwhelming majority of UK estate and letting agents: its 77 million monthly users and near-mandatory industry status mean that not listing on Rightmove is commercially self-defeating for most agencies. OnTheMarket is a credible supplementary portal in active audience-building mode, backed by CoStar Group's approximately £45–47M per year UK marketing investment. The right evaluation metric for agents considering OnTheMarket as a supplementary subscription is cost per completed instruction — not traffic rank or brand recognition. Agents who can demonstrate measurable instruction conversion from OTM leads at a competitive cost have a rational basis for the subscription; those who cannot should wait for OnTheMarket's consumer build to mature before committing.
- What did CoStar paying £99M for OnTheMarket actually change for UK agents?
- CoStar Group's £99M acquisition of OnTheMarket, completed in early 2024, transformed OnTheMarket from an agent-owned challenger with limited capital into a portal backed by one of the world's largest commercial real estate data companies. The immediate changes included relaxation of the 'Only With Us' listing exclusivity requirement, an approximately £45–47M per year UK sales and marketing commitment, and a new strategic direction focused on consumer audience-building rather than exclusivity-model differentiation. For UK agents, the practical implication is that OnTheMarket now has the capital to sustain a multi-year growth campaign — meaning the supplementary portal question should be evaluated with a longer time horizon than the pre-CoStar OTM position warranted.
- Do Rightmove and OnTheMarket carry the same listings?
- Not currently. Rightmove's approximately 980,000 active listings represent near-complete coverage of UK professionally marketed property, as Rightmove's near-mandatory agent status means virtually all UK estate and letting agents list there. OnTheMarket's approximately 14,000 agent branches represent a meaningful but incomplete UK agent coverage relative to Rightmove's near-universal base. Buyers searching only OnTheMarket will miss listings that professional agents have not yet added to the portal. CoStar's agent coverage investment is designed to close this gap, but listing parity with Rightmove is a multi-year target rather than a 2026 reality.
- Why did REA Group try to buy Rightmove rather than OnTheMarket?
- REA Group's 2024 takeover approaches for Rightmove — ultimately rejected at implied valuations approaching £6bn — targeted the UK's mandatory portal rather than a challenger because Rightmove's consumer network and near-mandatory agent status represent a market position that cannot be replicated by building from scratch. OnTheMarket, under Aidan Coldwell and the OnTheMarket plc board before the CoStar acquisition, was not in the same strategic position. REA Group — the parent of realestate.com.au and the attempted acquirer of Rightmove — chose to invest in the UK AI proptech challenger Jitty via a £2.8M 2025 seed round lead rather than making a direct bid for either Zoopla or OnTheMarket, suggesting REA sees the AI-first challenger segment as a separate strategic option from the incumbent portal market.
- What does CoStar's commercial real estate background mean for OnTheMarket's UK product?
- CoStar Group built its business on commercial real estate data analytics — its CoStar platform and LoopNet portal are dominant in US commercial property information. The potential integration of CoStar's commercial data capabilities into OnTheMarket could create a differentiated search experience for UK commercial property and mixed-portfolio searches that Rightmove, built primarily as a residential portal, does not currently replicate with the same data depth. However, as of 2026, CoStar's primary focus in the UK is building OnTheMarket's residential consumer audience and agent coverage rather than deploying commercial data products. The commercial data differentiation is a stated future opportunity rather than a currently delivered product advantage.