MarketSizer & BuiltWith
BuiltWith answers "what is this site running?" across the whole web. MarketSizer answers "whose subscription is about to change?" in the categories you sell into.
“Find out what websites are Built With.”
Source: builtwith.com homepage
What each tool does well
BuiltWith
Best known for
A deep, web-crawler-driven index of what technologies a website is using right now, plus a historical archive of when they first appeared.
Useful for
Teams that need to know which technologies an account has deployed today - for prospecting, competitive research, list building or market sizing.
MarketSizer
Best known for
Subscription intelligence - the state each subscription is in and when it is likely to change, on top of what is running.
Useful for
GTM teams whose real question is who is about to change tools, evaluate a competitor, or churn.
Where BuiltWith is strong
- One of the widest technographic footprints on the public web, indexing tens of thousands of technologies.
- Simple, well-known interface that reps can look up any single site in seconds.
- Historical detection archive of when a technology first appeared on a site.
- Well-priced compared with enterprise technographic providers, and a free lookup tool for individual sites.
- Widely used across sales, marketing, competitive research and market-sizing teams.
- Long-standing brand and dataset - one of the earliest technographic tools on the market.
Where they differ
Different jobs on the same pipeline - the overlap between BuiltWith and MarketSizer is smaller than a feature list suggests.
| Feature | BuiltWith | MarketSizer |
|---|---|---|
| What each tool tells you | ||
| Which technologies a site is running today | Included | Included |
| Historical record of when a technology first appeared or was removed | Included | Included |
| Whether a subscription is currently in a trial state | Not included | Included |
| Whether an account is evaluating a competitor | Not included | Included |
| Whether a subscription is approaching renewal | Not included | Included |
| Data coverage | ||
| Breadth (technologies indexed) | Tens of thousands of technologies | 200+ vendors deep, expanding across martech |
| Historical subscription-event dataset | Not included | 70M+ records |
| Active subscription counts | Not included | 17M+ active, 2.5M+ active trials |
| Signals & prioritisation | ||
| Event-based buying signals (trial, switch, churn, renewal) | Not included | Included |
| Account prioritisation score | Not included | Included |
| Category-level competitive tracking | Trends reports over time | Live subscription events per account |
| Workflow | ||
| Chrome-extension side panel in HubSpot, Salesforce, LinkedIn and Apollo | Site-lookup extension | Included |
| Push accounts into CRM | Via API and exports | Included |
| Flat-fee bulk exports | Included | Per-unlock credit model |
| Commercial | ||
| Entry-level pricing | Published on builtwith.com | Credit-based - see pricing page |
| Free single-site lookup | Included | Free trial |
MarketSizer pricing as published at marketsizer.io/pricing. BuiltWith details as published on their own site and public documentation, last checked 8 August 2026. Spotted something out of date? Tell us and we will fix it.
Where each tool earns its place
Lean on BuiltWith when
- Your core question is which technologies an account has installed, across any category on the web.
- You are running one-off competitive research or ad-hoc account lookups.
- Breadth of technology coverage matters more to you than depth per account.
- Bulk exports and API access into your own models matter more than an in-CRM feed.
- You want a free lookup tool your whole team can use without a paid plan.
Add MarketSizer when
- The question you are paid to answer is what is changing, and when.
- You want trial, switch, renewal and churn signals attached to each account.
- You want accounts ranked by an Opportunity Score reps can act on this week.
- You want signals delivered alongside HubSpot, Salesforce, LinkedIn and Apollo, not in a separate lookup tool.
- Timing is the primary lever in your GTM motion - who is about to buy matters as much as who has the tech.
How MarketSizer works with BuiltWith
BuiltWith builds the universe; MarketSizer tells you which corner of it is moving. Technographic breadth answers who could buy from you - subscription events answer who is likely to buy now. Run in sequence, one output becomes the other’s input.
Build the universe in BuiltWith
Technographic filters produce the full list of companies running the technologies you sell against or alongside.
Import the list into MarketSizer
CSV import brings the BuiltWith universe into MarketSizer as tracked accounts - bulk upload handles large lists.
MarketSizer adds the timing layer
Each account is ranked by observable buying events - trials, switches, churns and renewal windows - into an Opportunity Score.
Work the list in event order
Reps start with the accounts whose subscriptions are changing now, instead of working a static technographic list alphabetically.
What buyers say about the category
Themes from GTM leaders currently evaluating tools in this space.
Nobody needs BuiltWith explained to them; it has been the reference technographic index for a decade and the buyers we speak to already use it well. Where the conversation turns is the lifecycle question. Present-tense detection says a tool is installed. It stays silent on whether the renewal is next quarter, whether something else in the stack just churned, and what the account has been evaluating. Teams keep BuiltWith for the first question and add MarketSizer for the second.
“Technographic tools show me what is installed. What I cannot see is the state of the subscription behind it: is a renewal coming, did they drop something recently, what else have they looked at this year?”
“We have dipped in and out of half a dozen signal sources over the years, none of them consistently. What we want is one place where those signals land already joined up.”
MarketSizer & BuiltWith - frequently asked questions
Why is subscription state different from technographic detection?
Technographic detection tells you a technology is present on a site. Subscription state tells you where the account is in its lifecycle with that technology - trialling it, mid-contract, evaluating a replacement, approaching renewal. The second is what unlocks timing-based outreach.
How does BuiltWith’s coverage compare with MarketSizer’s?
BuiltWith is far broader, indexing tens of thousands of web technologies, but shallower per account. MarketSizer goes deeper: 200+ vendors in Customer Support, Live Chat and adjacent categories, with deep subscription history per account and 70M+ historical events indexed. And the coverage is expanding - we are releasing new categories continuously, with the goal of covering the whole martech space.
Can BuiltWith and MarketSizer coexist?
They can. Some teams keep BuiltWith for one-off deep lookups across many technology categories and use MarketSizer as the day-to-day account-prioritisation surface for the categories they sell into.
How does pricing compare?
BuiltWith publishes its plan pricing on builtwith.com - check there for current figures. MarketSizer is credit-based (see current plans), with no per-seat multiplier. Both are self-serve to start; pricing then diverges based on how deeply you use each tool.
Is MarketSizer trying to replace BuiltWith?
Not directly. If your primary need is a broad technology-install snapshot across the whole web, BuiltWith remains a strong fit. MarketSizer is the better fit when timing signals and event-based subscription intelligence matter more than raw coverage breadth.
See how MarketSizer works with your BuiltWith stack.
30 minutes on your accounts, tailored to your ICP. We show which companies are trialling, switching or renewing right now, so you can see whether the timing signal changes what your team does next.
500 credit trial No credit card Live data, not a slide deck
BuiltWith and all other product names, logos and brands referenced on this page are trademarks of their respective owners, used for identification and comparison purposes only. No endorsement or affiliation is implied.