Every client site, every stack,
one tool
WP Umbrella is the WordPress maintenance tool for agencies whose client portfolio is 100% WordPress. SiteLetter is for everyone else: even one Webflow, Framer, Squarespace, Shopify, or custom-built client puts you in mixed-stack territory, where you would otherwise be paying for WP Umbrella plus a second tool to cover the non-WP sites. SiteLetter is the one-tool answer.
Also evaluating Oh Dear, UptimeRobot, or StatusCake? See those comparisons, or browse all alternatives.
Quick verdict
This is the comparison page where the answer depends entirely on what is in your client portfolio.
100% WordPress agencies
All your client sites are WordPress, and your monthly maintenance retainer covers plugin updates, backups, and security as much as monitoring. WP Umbrella ships those WordPress-native features SiteLetter does not: plugin/theme updates with rollback, encrypted backups with 50-day retention, PHP error monitoring, one-click admin access, database optimisation.
WP Umbrella's base plan is €1.99/site a month (about $2.19 USD). SiteLetter with every monitor on is $4.80/site a month. For a pure-WP shop that gap is real, and it is stated plainly here rather than buried.
Mixed-stack agencies
Your client portfolio includes Webflow sites, Framer pages, Squarespace stores, Shopify storefronts, Next.js apps, or custom HTML alongside WordPress. WP Umbrella cannot monitor any of those. SiteLetter monitors each client website per-domain (auto-discovering up to 15 pages each), regardless of platform underneath, in one tool, with one bill, with one report shape across the whole portfolio (one report per site).
SiteLetter also goes deeper on each page: Lighthouse with all four scores, AI day-over-day visual regression, and a broken links and images check on every monitored page, with the results landing in a scheduled white-label email report built to forward every week.
WP Umbrella pricing, checked
WP Umbrella sells one plan, priced per WordPress install, and two add-ons you can put on top of it. It is WordPress maintenance first, with monitoring alongside.
| Plan | Price | What it covers |
|---|---|---|
| Base plan | €1.99 per site a month, or $2.19 in US dollars | Their one plan, with no feature tiers: WordPress updates with rollback, encrypted backups with 50-day retention, uptime, PHP error and vulnerability monitoring, and white-label PDF reports. |
| Security add-on | €2 per site a month | A firewall with virtual patching, daily malware scanning, an IP blocklist and an activity log. |
| Hourly Backups add-on | €2.49 per site a month | Hourly backups, on top of the ones the base plan carries. |
Source: wp-umbrella.com/pricing Pay as you go, with no site minimum, on WordPress installs only. Only the base plan is published in both currencies, and its dollar rate was last read on August 31, 2026; both add-ons are published in euros only. Read from their pricing page on .
- 10 client sites with every monitor on: $48.00 a month, for up to 150 pages.
- Switch a monitor off for a site and that site costs less. See every rate.
- Prepaid credits, no subscription. If they run out, monitoring stops, and you are warned before it does.
Which is cheaper, and for what
Per site, WP Umbrella is cheaper. Their base plan is €1.99 a month, or $2.19 in their dollar price, against SiteLetter's $4.80 with every monitor on. For a WordPress-only agency whose retainer is maintenance, that gap is real.
What the SiteLetter figure buys that theirs cannot is the same monitoring on sites that are not WordPress: Webflow, Shopify, custom builds.
Where WP Umbrella genuinely wins
WP Umbrella is purpose-built for WordPress and the depth shows. If your portfolio is entirely WordPress and the retainer is built around maintenance, these are the features that make it the stronger fit.
WordPress maintenance suite (updates, backups, database optimisation)
Bulk plugin and theme updates with rollback across the whole client portfolio, encrypted backups (50-day retention bundled, hourly add-on at €2.49/site) with one-click restore, and database optimisation. SiteLetter does not run inside WordPress and ships none of this.
PHP error monitoring + one-click admin access
WP Umbrella monitors PHP errors on each install automatically, grouped with stack traces, and gives one-click admin access into each client WordPress dashboard. SiteLetter is external monitoring, not a WordPress dashboard.
Security: vulnerability monitoring, plus an optional add-on
Vulnerability monitoring against the Patchstack database is in the base plan. The Security add-on at €2/site/month adds a firewall with virtual patching, daily malware scanning, an IP blocklist and an activity log. SiteLetter does not ship security scanning.
Where SiteLetter is the right pick
For mixed-stack agencies (anyone whose client portfolio is not 100% WordPress), these are the things SiteLetter is shaped for that WP Umbrella is not.
Platform-agnostic monitoring (Webflow, Shopify, Next.js, custom HTML)
Every monitoring service in SiteLetter runs externally against the live website, not against a WordPress install. You add a domain; SiteLetter discovers and monitors up to 15 pages of it. That same flow works for a Webflow site, a Framer page, a Squarespace store, a Shopify storefront, a Next.js app on Vercel, or a static HTML site on Cloudflare Pages, with exactly the same treatment as a WordPress site. WP Umbrella does not support any of these.
Lighthouse with the four-score breakdown, not generic "performance monitoring"
WP Umbrella lists "Performance monitoring (desktop & mobile)" on its features page, and its pricing page words the same line "Google PageSpeed & response time monitoring", but neither page describes a per-page Google Lighthouse audit with the Performance, Accessibility, SEO, and Best Practices breakdown across every monitored page. SiteLetter runs the full Lighthouse on every monitored page across every site, every day. DNS, TLS, and CDN caches are pre-warmed before each audit so the score is stable enough to ship in a client report. Without that warmup an audit is partly measuring the state of those caches rather than the page, and two scores taken under different cache conditions are not comparable.
Continuous visual regression, not an update-time check
WP Umbrella runs visual regression testing as part of its Safe Updates flow: its features page says each update "runs through visual regression testing, cache clearing, and database upgrade verification, and rolls back automatically if anything breaks." That answers whether an update broke the page, which is useful for the update moment. It is not a continuous day-over-day comparison. SiteLetter captures a full-page screenshot of every monitored page on both mobile and desktop every 24 hours regardless of whether anyone deployed anything, and sends any diff above the noise floor to an AI classifier. Rotating ads and cookie banners get dismissed as cosmetic noise. A real layout shift, whether caused by an update, a stylesheet change, or a CDN config drift, is flagged in the dashboard as soon as the next daily scan completes and called out in the report you forward.
White-label emails, not white-label PDFs
WP Umbrella ships automated white-label PDF reports with custom branding. SiteLetter ships scheduled email reports, white-label for each client: your logo, your brand colour, custom footer text, your reply-to address, and your agency name as the sender on every send. The recipient opens the report from their inbox with no SiteLetter login screen, and an org-level toggle removes the SiteLetter logo, wordmark and footer from the report itself. Plus a drag-and-drop builder to reorder sections per report schedule.
One bill for the whole portfolio, not WP Umbrella plus a second tool
Agencies that pick WP Umbrella end up needing a second monitoring tool for non-WordPress clients - such as Oh Dear, UptimeRobot, or a hand-rolled check - which means a second subscription, a second dashboard, and a second weekly cadence to integrate into the client report. SiteLetter covers WordPress and non-WordPress the same way, in one dashboard, with one bill, with one report shape across the whole portfolio.
Per-page coverage, not per-install pings
WP Umbrella lists uptime monitoring per site, and its pages do not describe checks on individual pages. If the FAQ page's Lighthouse just crashed to 41, the pricing page's hero image 404'd this morning, or a plugin update pushed the contact form below the fold, a site-level uptime check does not tell you. SiteLetter auto-discovers up to 15 important pages per site via sitemap and link graph, then runs Lighthouse, visual regression and broken-asset checks over every one of them, every day. Uptime is its own service and watches the homepage, every minute. A second region re-checks any failure before an alert fires, and a third breaks a tie when the two disagree.
Feature-by-feature comparison
The full picture, grouped by category. The "WordPress maintenance" group is all WP Umbrella; the "Per-page monitoring" group is all SiteLetter. The honest answer for a mixed-stack agency is often "both, used together."
| Feature | SiteLetter | WP Umbrella |
|---|---|---|
| Stack scope | ||
| WordPress sites | Yes (external monitoring) | Yes (deep integration, maintenance + monitoring) |
| Joomla / Drupal sites | Yes (external monitoring) | No |
| Webflow / Framer / Squarespace / Shopify sites | Yes | No |
| Static HTML / Next.js / Astro sites | Yes | No |
| Cross-platform monitoring (any website stack) | Yes (per site, 15 pages auto-discovered, external monitoring) | No (WordPress only) |
| Pricing model | ||
| Pricing unit | 1 site (up to 15 pages) | 1 WordPress install |
| Every monitor on | $4.80/site a month (15 pages monitored); less per site if it runs fewer of them | €1.99/site/mo (~$2.19 USD), one plan with no feature tiers; security (€2/site) and hourly backups (€2.49/site) sold separately |
| Free start | 14 days on 1 site, no card | Free trial, no credit card required |
| WordPress maintenance: where WP Umbrella goes deepest | ||
| Plugin and theme updates with rollback | No | Yes |
| Encrypted automated backups | No | Yes (50-day retention; hourly backups add-on) |
| PHP error monitoring with stack traces | No | Yes |
| One-click admin access | No | Yes |
| Database optimisation | No | Yes |
| Security (vulnerability monitoring; Security add-on) | No | Vulnerability monitoring in the base plan; firewall with virtual patching and daily malware scanning on the €2/site/mo Security add-on |
| Per-page monitoring: where SiteLetter goes deepest | ||
| Uptime checking | Homepage every 1 min from the EU, confirmed from a second region on failure; all 15 monitored pages reached daily by the scan | Uptime monitoring per site; no per-page checks described on their pages |
| Google Lighthouse audits (Performance / Accessibility / SEO / Best Practices) | Every monitored page, daily, with cache warmup | "Performance monitoring (desktop & mobile)" per their features page, worded "Google PageSpeed & response time monitoring" on their pricing page; no per-page Lighthouse four-score breakdown described |
| AI day-over-day visual regression with classification | Every monitored page, daily, classified | Visual regression testing as part of Safe Updates (update-time); no continuous day-over-day check described |
| Broken asset detection across pages | Every monitored page, daily | Yes - "Broken links & images monitoring": scheduled link and image checks across pages, posts and media, tracked over time, on the WordPress installs it manages |
| Core Web Vitals (LCP, CLS) | Yes (via Lighthouse) | Not named on their pricing or features pages; their line is "Performance monitoring (desktop & mobile)" |
| Site-level services | ||
| SSL certificate expiry alerts | Yes | Yes |
| Domain expiry alerts | Yes | Yes |
| Sitemap auto-discovery | Yes (weekly sync) | N/A (per-site monitoring) |
| Monitoring data retention | 2 years (730 days) of scan, screenshot, Lighthouse and report history, counted from the last day the account funded any monitoring; raw uptime check rows kept 280 days (incidents retained) | Backups: 50 days; monitoring data retention is not listed on their pricing or features pages |
| Client-facing reports | ||
| Scheduled client-facing email report | Yes (weekly, bi-weekly, monthly, quarterly) | Automated white-label PDF reports with custom branding, per their features page as of September 2026 |
| Per-client branding (logo, color, reply-to) | Yes | White-label PDFs with custom branding |
| Remove vendor branding from the report | Yes (white-label reports: an org-level toggle removes the SiteLetter logo, wordmark and footer from the report body, and reports are sent from your own domain once you verify it, under your agency name) | Yes (white-label reports) |
| Drag-and-drop report builder | Yes | Not listed on their pricing or features pages |
| Recipients view reports without a login | Yes - the white-label report renders inside the email, and every report carries a public link that opens without an account. | Yes (a white-label PDF needs no login) |
Sources: wp-umbrella.com/pricing, wp-umbrella.com/features. Verified against their features page and the euro view of their pricing page; the dollar base rate was last read August 31, 2026.
Which job are you buying for?
Comparing monitor counts flatters whoever wrote the comparison. These are the two questions that actually decide it, at 10 client sites.
For uptime alone, WP Umbrella is a complete answer
WP Umbrella's base plan carries uptime with it, alongside WordPress plugin and theme updates, encrypted backups and PHP error monitoring, on every install it manages. For a pure-WordPress agency whose retainer is maintenance first, that is a complete answer, and this page says so rather than burying it.
SiteLetter can be bought that way too, since uptime is a line item you can switch on without the rest. But uptime alone is not the job this page is about, and pretending otherwise would mean pricing around a comparison you can run yourself in a minute.
Lighthouse, visual change detection, a branded report
WP Umbrella is WordPress only, so a Webflow page, a Squarespace store or a custom build is not monitorable at any price. Within WordPress its published pages describe no Lighthouse four-score breakdown and no day-over-day visual change detection (its visual regression testing runs as part of Safe Updates), and matching the checks on this page needs their security and hourly-backup add-ons on top of the base rate.
10 client sites with every monitor on, covering up to 150 monitored pages. Prepaid, nothing recurring.
WP Umbrella figures are the ones that vendor publishes, in the currency they publish them. Verified .
When to pick which
Three honest scenarios.
100% WordPress agency
All your client sites are WordPress and your retainer includes maintenance (updates, backups, security). WP Umbrella ships exactly the right product from €1.99/site/mo base, with firewall and malware scanning as a €2/site Security add-on, and WP-native features SiteLetter does not have. Honestly the better pick.
Mixed-stack agency
Your portfolio mixes WordPress with Webflow, Framer, Squarespace, Shopify, custom builds. WP Umbrella does not monitor any of the non-WP sites. SiteLetter monitors all of them the same way in one tool, plus ships Lighthouse, AI visual regression, and white-label weekly client reports across the entire portfolio.
Mixed-stack with heavy WP maintenance
Mixed stack but the WordPress side still needs updates, backups, and rollback. Run both: WP Umbrella for WordPress maintenance, SiteLetter for cross-platform monitoring and the branded client report. They do overlap: uptime, performance, SSL and domain expiry, broken links and images, and the whole client-reporting row group above appear on both sides, and WP Umbrella ships white-label client reports of its own. The difference is shape rather than absence. WP Umbrella works from inside WordPress and owns maintenance; SiteLetter watches any stack from outside and goes deeper on each page.
SiteLetter vs WP Umbrella: FAQ
It depends on what the retainer covers. WP Umbrella's base plan is €1.99/site/month (about $2.19 USD), cheaper per site than SiteLetter with every monitor on at $4.80/site a month, and it ships WordPress-native features SiteLetter does not: backups, plugin and theme updates with rollback, PHP error tracking, one-click admin access, database optimisation. If 100% of your client work is WordPress and your client deliverable is "WordPress maintenance" (updates, backups, security), WP Umbrella is built for exactly that. SiteLetter's strength is mixed-stack monitoring plus the reporting deliverable, and it does not handle WordPress updates or core maintenance, so the two answer different halves of the retainer.
WP Umbrella is explicitly WordPress-only: their pricing page is titled "Build & Sell Care Plans for WordPress from €1.99/site", and every feature on it runs inside a WordPress install. If your client portfolio includes Webflow sites, Framer pages, Squarespace stores, Shopify storefronts, custom HTML/CSS sites, Next.js apps, or anything that is not a WordPress install, WP Umbrella cannot monitor them. SiteLetter is platform-agnostic: you add a domain, SiteLetter discovers up to 15 pages of it and monitors them externally, regardless of the stack underneath. For agencies that take on whatever client wants to hire them, that is the difference between one tool and two.
WP Umbrella lists "Performance monitoring (desktop & mobile)" on its features page and words the same line "Google PageSpeed & response time monitoring" on its pricing page, so page-speed tracking is there, but neither page describes a per-page Google Lighthouse audit with the Performance / Accessibility / SEO / Best Practices breakdown across every monitored page. SiteLetter runs full Lighthouse on every monitored page daily with cache warmup, and the four-score breakdown ships in the weekly client report.
WP Umbrella has visual regression testing, but it runs as part of Safe Updates: their features page says each update "runs through visual regression testing, cache clearing, and database upgrade verification, and rolls back automatically if anything breaks." It is not a daily monitoring sweep that screenshots every monitored page each day and diffs against yesterday to catch silent breakage between updates. SiteLetter takes a daily screenshot of every monitored page and compares it against the most recent clean capture. Anything past the noise threshold goes to an AI classifier, which calls it routine dynamic content, an intentional change, or real breakage. Different shape of feature with the same name.
A lot, if you are a WordPress agency: encrypted backups with 50-day retention and one-click restore, rollback for plugin or theme updates, PHP error monitoring grouped with stack traces, one-click admin access, database optimisation, Safe Updates with visual regression testing, vulnerability monitoring in the base plan, and an optional Security add-on (€2/site/month) that adds a firewall with virtual patching and daily malware scanning. SiteLetter does not do WordPress updates, backups, or core maintenance. SiteLetter monitors the running site externally, which catches outages, performance regressions, and visual changes, but it does not touch the WordPress install itself.
Cross-platform monitoring: any website stack including Webflow, Framer, Squarespace, Shopify, custom builds, alongside WordPress (WP Umbrella requires its plugin and only works on WordPress installs). AI day-over-day visual regression that classifies each diff big enough to matter as noise / intentional / breakage (WP Umbrella's visual regression testing runs as part of Safe Updates, not as continuous day-over-day classified diffing across all monitored pages). Sitemap auto-discovery: add a domain, SiteLetter picks the 15 most important pages and every monitor turns on for them. Branded scheduled per-client email reports with per-client logo, brand color, reply-to.
Yes, and on a mixed stack the split is a clean one. WP Umbrella for the WordPress maintenance side (updates, backups, plugin rollback, PHP errors on WP installs) and SiteLetter for the cross-platform monitoring and branded client reports. They do overlap: uptime, performance, SSL and domain expiry, broken links and images, and the whole client-reporting group appear on both sides, and WP Umbrella ships white-label client reports of its own. The difference is shape rather than absence. WP Umbrella works from inside WordPress and owns maintenance; SiteLetter watches any stack from outside and goes deeper on each page. If you are paying for both, the math only works once you have a mix of WP and non-WP clients large enough to justify it (rough rule of thumb: more than a few non-WP clients).
No. WP Umbrella's base plan is €1.99/site/month (about $2.19 USD); SiteLetter with every monitor on is $4.80/site a month. For a pure-WP agency at 20 client sites, WP Umbrella is about $44/mo and SiteLetter with every monitor on is $96.00/mo. That gap is real, and it is stated plainly here rather than buried. SiteLetter's pitch is not "cheaper per site" but "fewer tools for mixed-stack work plus an agency-deliverable report built to forward." If both of those are true for your agency, the math works out; if you are 100% WordPress and your client deliverable is updates and backups, WP Umbrella wins on cost.
Yes if you are moving toward mixed-stack work, but read this carefully: SiteLetter does not replace WordPress maintenance. SiteLetter does not handle plugin updates, backups, rollback, or PHP error tracking. If you are leaving WP Umbrella for SiteLetter without keeping another WordPress maintenance tool, your clients lose update management and backups. The honest move for most mixed-stack agencies is to keep WP Umbrella (or similar) on WordPress sites and add SiteLetter for the cross-platform monitoring and reporting. New accounts get 14 days of full monitoring on one site with no card, so add one non-WordPress client site (a Webflow page, a Squarespace store) to validate the cross-platform experience before extending.
Still have questions? Get in touch.
Comparison based on publicly available WP Umbrella pricing and feature documentation, last verified . WP Umbrella is a trademark of its respective owner, used here for identification and comparison purposes only. SiteLetter is independent and not affiliated with, sponsored by, or endorsed by WP Umbrella. For the most current WP Umbrella pricing and feature information, see wp-umbrella.com.
You set up care-plan reporting once.
After that it runs without you.
SiteLetter is the kind of tool you forget you're using, until your client thanks you for the report you didn't write.
- ✓ Just add a domain. SiteLetter auto-discovers pages, starts monitoring, schedules reports. You pick your alert rules and who gets each report.
- ✓ No scripts to install. SiteLetter monitors from the outside, like a real visitor.
- ✓ Nothing recurring. No subscription, no contract. You buy credits when you want them and each site spends its own.