WP and Joomla,
plus everything else
Watchful is a WordPress and Joomla maintenance platform with monitoring layered on top. SiteLetter is cross-platform monitoring with AI day-over-day visual regression and Lighthouse on every monitored page. Both built for agencies, different jobs.
Also evaluating WP Umbrella, Oh Dear, or StatusCake? See those comparisons, or browse all alternatives.
Quick verdict
Both tools are agency tools. The decision is about which agency job your retainer is built around.
WordPress / Joomla maintenance agencies
Your client retainer covers WordPress and Joomla maintenance: plugin updates, security scanning, backups, intrusion monitoring. Watchful is purpose-built for that job with deep CMS integration. At $1.83/site/month for Premium, it is cheaper per site than SiteLetter with every monitor on at $4.80/site a month.
Also has a free tier with reduced limits that suits smaller agencies running on $0/mo.
Cross-platform monitoring agencies
Your retainer is about monitoring depth and the monthly client deliverable: Lighthouse on every monitored page, AI day-over-day visual regression that filters cosmetic noise, white-label weekly reports built to forward. Your portfolio is mixed-stack (Webflow, Framer, Squarespace, custom, alongside WordPress) and Watchful cannot monitor most of those.
SiteLetter at $4.80/site a month with every monitor on covers every monitored page on every site, regardless of the stack underneath.
Where SiteLetter is the better fit
SiteLetter and Watchful are both agency tools, but they ship different feature sets. These are the things SiteLetter does that Watchful does not, framed around the agency monitoring deliverable rather than the CMS maintenance side.
Daily screenshot diffs across every page, regardless of stack
Watchful runs CMS-aware checks inside WordPress and Joomla installs. What it does not do is take a daily screenshot of a Webflow homepage, a Squarespace product page, or a Next.js marketing page and diff it against the last good capture of it, normally yesterday's. SiteLetter does that for every monitored page on every site. An AI classifier sorts each change above your sensitivity threshold: rotating banners and cookie notices get dismissed as cosmetic noise; a genuine content change lands in the next scheduled client report; a broken layout, missing image, or 404'd stylesheet is flagged in the dashboard after the next daily check and called out in that report.
Lighthouse on every monitored page, not listed in Watchful's published features
Watchful's feature set is maintenance-shaped: bulk updates, backups, activity logs, security scans. Google Lighthouse audits on monitored pages are not referenced in their published feature materials (checked August 21, 2026). With every monitor on, SiteLetter runs the full Lighthouse (Performance, Accessibility, SEO, Best Practices) plus Core Web Vitals (LCP, CLS) on every monitored page across every client site daily, and pre-warms DNS, TLS, and CDN caches before each audit, so each score is taken under the same conditions as the one before it and is stable enough to ship in a client deliverable.
One tool covers your whole portfolio, not just WordPress and Joomla
Watchful's own footer states the supported stacks: WordPress and Joomla. Drupal, Webflow, Framer, Squarespace, Shopify, Next.js, Astro, custom HTML are out of scope. SiteLetter monitors any of those the same way: paste a domain, SiteLetter discovers up to 15 pages from its sitemap and homepage links, and books the first scan for the next free quarter-hour, usually within minutes, with the SSL and domain expiry readings on that same scan. For a mixed-stack agency, that is one dashboard and one bill instead of Watchful for the WP half plus a second tool for everything else.
Monitoring per page, not per install
Watchful's monitoring runs at the install level: the WordPress install is up, plugins are current, security scan is clean. The FAQ whose Lighthouse Performance just dropped to 41, the product page whose hero image silently 404's, the pricing page a plugin update pushed out of shape - those are page-level signals an install-level monitor cannot surface, and a daily pass over the page itself is what catches them. SiteLetter auto-discovers up to 15 important pages per site (depth, homepage links, sitemap priority, recency) and, with every monitor on, 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.
Branded email reports without a SiteLetter login
Watchful generates white-label PDFs with your name and logo and a scheduled emailer to send them. SiteLetter's flow runs a step deeper: per-client logo, brand colour, and custom reply-to address on every scheduled email; optional org-level toggle that removes the SiteLetter brand from the report body. The recipient opens the report straight from their inbox, under your agency's name, logo and reply-to address, on the cadence you set.
Builder wired to the AI-classified weekly content
Watchful's report builder generates PDFs for download or scheduled send. SiteLetter's builder is wired into the AI classification pipeline directly: when you reorder Page Scores, Uptime, Visual Changes, Renewals, and Content Health, the Visual Changes section pulls from the already-classified daily diffs (cosmetic noise filtered out, intentional updates summarised, real breakage highlighted). The result is a weekly digest written for a non-technical client, not a PDF appendix.
Feature-by-feature comparison
The full picture, grouped by category. The "Per-page monitoring" group is mostly SiteLetter; the "WP/Joomla maintenance" group is mostly Watchful. For some mixed-stack agencies the honest answer is "both, used together."
| Feature | SiteLetter | Watchful |
|---|---|---|
| Stack scope | ||
| WordPress sites | Yes (external monitoring) | Yes (deep integration, maintenance + monitoring) |
| Joomla sites | Yes (external monitoring) | Yes (deep integration) |
| 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 domain, 15 pages auto-discovered, external monitoring) | No (WordPress + Joomla only) |
| Pricing model | ||
| Pricing unit | 1 site (up to 15 pages) | 1 site (per CMS install) |
| Every monitor on | $4.80/site a month (15 pages monitored); less per site if it runs fewer of them | $1.83/site/mo Premium, pay-as-you-go |
| Free start / Free tier | 14 days on 1 site, no card | Permanent free tier (reduced limits) |
| Per-page monitoring (SiteLetter territory) | ||
| 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 | 1 URL per site (typically the homepage) |
| Google Lighthouse audits (Performance / Accessibility / SEO / Best Practices) | Every monitored page, daily, with cache warmup | Not referenced in their public feature materials |
| AI day-over-day visual regression with classification | Every monitored page, daily, classified | Not in product |
| Broken asset detection across pages | Every monitored page, daily | Their SEO audit checks broken links among other on-page items; no broken-image or per-page asset check is published |
| Core Web Vitals (LCP, CLS) | Yes (via Lighthouse) | No |
| WordPress / Joomla maintenance (Watchful territory) | ||
| Bulk plugin and theme updates | No | Yes (one-click, across portfolio) |
| Security and malware scanning | No | Yes (90-day history on Premium) |
| Backup scheduling (local + cloud) | No | Yes |
| CMS activity log retention (plugin/theme/user actions) | No | 1 month (Free) / 24 months (Premium) |
| Early-warning intrusion scan | No | 1/day (Free) / 8/day (Premium) |
| Remote plugin enable/disable | No | Yes (Premium) |
| Site-level services | ||
| SSL certificate expiry alerts | Yes | Yes (Premium) |
| Domain expiry alerts | Yes | SSL expiry only (Premium); no domain expiry |
| Sitemap auto-discovery | Yes (weekly sync) | N/A (per-site monitoring) |
| Monitoring data retention | 2 years (730 days) for Lighthouse, screenshots, asset checks, reports and uptime incidents; raw uptime check rows kept 280 days | Activity log: 1 month Free / 24 months Premium; security scan history: 7 days Free / 90 days Premium; uptime retention not published |
| Client-facing reports | ||
| Scheduled client-facing email report | Yes (weekly, bi-weekly, monthly, quarterly) | Scheduled reports (weekly, monthly, quarterly), PDF download |
| Per-client branding (logo, color, reply-to) | Yes | White-label with name and logo |
| Remove vendor branding from the report | Yes (white-label reports) | Yes (white-label reports) |
| Drag-and-drop report builder | Yes | Yes (PDF report builder) |
| 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. | Scheduled email / PDF delivery |
| Platform features | ||
| Single sign-on (SSO) | No SAML or OIDC login | Yes (Premium), but a different thing: one Watchful login that provisions admin users ACROSS your managed WordPress and Joomla sites, not SAML or OIDC into Watchful itself |
| Public REST API | Not available | Yes (Premium) |
| Agency multi-client dashboard | Yes | Yes (Premium) |
| Native mobile app | No | No |
Sources: watchful.net/features, verified , and watchful.net/pricing, read on .
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, Watchful is a complete answer
Watchful has a permanent free tier with reduced limits, and its paid plans cover uptime, security scanning, bulk updates and a PDF report builder across every install. For a WordPress and Joomla shop that is a lot of ground for the money.
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
Watchful covers WordPress and Joomla installs only, so nothing outside those two stacks is monitorable. It has no Lighthouse four-score breakdown, no day-over-day visual change detection, and domain expiry alerts are not in the product.
10 client sites with every monitor on, covering up to 150 monitored pages. Prepaid, nothing recurring.
Watchful figures are the ones that vendor publishes, in the currency they publish them. Verified .
Where Watchful genuinely wins
Watchful has been operating for over a decade as a WordPress and Joomla maintenance platform. The depth of the maintenance side shows. For pure WP/Joomla agencies whose retainer is built around maintenance and security, Watchful is the stronger fit. The wins below are real and SiteLetter does not match them.
WordPress and Joomla maintenance built in
Bulk plugin and theme updates across the entire client portfolio, with one-click execution. Activity logging (24-month retention on Premium, per their published pricing page as of August 2026), remote plugin enable/disable, and an installer that pushes plugins to multiple sites at once. SiteLetter does not run inside WordPress or Joomla and does not handle maintenance at all.
Security and blacklist scanning
Security scans with 90-day history on Premium, blacklist checks against known threat feeds, and an early-warning intrusion scan running 8 times per day on Premium. Useful for agencies whose clients expect security as part of the retainer. SiteLetter does not ship security scanning.
Backup scheduling with local and cloud destinations
Backup scheduling built into the maintenance layer with both local and cloud storage options. Bundled in the Premium tier. SiteLetter does not run backups; SiteLetter monitors running sites externally.
Free tier suitable for small agencies
Watchful's free tier includes activity logging, security scanning, bulk updater, and report builder with PDF download. Smaller activity-log retention (1 month vs 24 months on Premium) and reduced security-scan history (7 days vs 90), but enough for a small agency to run on $0/mo. SiteLetter starts you with 14 days of full monitoring on one site, then you buy credits.
Established product with a decade-plus track record
Watchful has been operating for over a decade as a WordPress and Joomla maintenance platform. Loyal agency user base. Enterprise procurement teams sometimes need vendor-tenure assurance that a newer product cannot match.
Report emails can leave from your own domain
Watchful's published pricing lists "Email Reports from Custom Domain" on its Premium plan (checked August 2026), so the report your client receives can leave the agency's domain. SiteLetter's reports are white-label: your logo, your brand colour, your reply-to address, and your agency name as the sender, with the SiteLetter name taken off by one toggle, sent from your own domain once you verify it, on every site at no separate rate.
Cheaper per site than SiteLetter with every monitor on
Watchful Premium is $1.83/site/month. SiteLetter with every monitor on is $4.80/site a month. For pure WordPress/Joomla agencies that do not need Lighthouse, day-over-day visual regression, or cross-platform monitoring, that per-site gap is real. A comparison page that hid it would not be worth reading.
When to pick which
Two honest scenarios.
Any agency that wants modern monitoring + white-label reports
Whether your portfolio is mixed-stack (WordPress + Webflow + Squarespace + custom) or pure WP/Joomla, if the deliverable you owe is per-page Lighthouse, AI day-over-day visual regression, and a branded weekly report, SiteLetter is built for that job. Watchful's monitoring is install-level uptime and SSL expiry; per-page Lighthouse and classified day-over-day visual diffs are the wedge.
Pure WP/Joomla maintenance agency
All your clients are on WordPress or Joomla and your retainer is built around maintenance: bulk plugin updates, backups, security scanning, intrusion detection. Watchful is purpose-built for that and cheaper per site than SiteLetter with every monitor on. SiteLetter does not do CMS maintenance.
SiteLetter vs Watchful: FAQ
Watchful is built around WordPress and Joomla maintenance (updates, backups, security scanning), with uptime and SSL monitoring layered on top. Their public materials do not reference Google Lighthouse audits with Performance / Accessibility / SEO / Best Practices score breakdowns per monitored page. SiteLetter runs full Lighthouse on every monitored page on every site daily with cache warmup, and the four-score breakdown ships in the client report as the Page Scores section; Core Web Vitals (LCP and CLS) are collected and shown in the dashboard.
No. Watchful's feature set covers WordPress/Joomla maintenance, security and blacklist scanning, scheduled reports, and uptime monitoring. It does not screenshot pages once a day and diff them against yesterday with AI classification of changes. SiteLetter does: a daily screenshot of every monitored page is compared to the last good capture, normally yesterday's, and AI classifies each diff big enough to matter as noise (rotating banners), an intentional update (logged in the weekly report), real breakage (missing images, layout collapse, flagged in the dashboard and called out in the report you forward), or couldn't-verify.
No. Watchful's own footer states: "Watchful currently supports WordPress and Joomla." If your client portfolio includes Drupal, Webflow, Framer, Squarespace, Shopify, custom HTML, Next.js apps, or any non-WP/Joomla stack, Watchful cannot monitor them. SiteLetter takes a domain and discovers up to 15 pages of it, then checks each one externally every day regardless of the stack underneath: Lighthouse audits via headless Chrome, screenshots, broken-asset checks. Uptime probes 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. The same coverage shape across WordPress, Joomla, and everything else.
No. Watchful Premium is $1.83/site/month; SiteLetter with every monitor on is $4.80/site a month. Watchful also has a free tier (with reduced limits on activity log retention, security scan history, and early-warning scans). For pure WordPress + Joomla agencies that need maintenance plus basic uptime monitoring, Watchful is cheaper per site than SiteLetter with every monitor on. SiteLetter's pitch is not "cheaper per site" but "deeper per-page monitoring (Lighthouse, AI visual regression) plus cross-platform coverage." The per-site math only works for SiteLetter when those features matter to your client deliverable.
WordPress and Joomla maintenance: bulk plugin and theme updates across your portfolio, security and malware scanning, backup scheduling with local and cloud destinations, activity logging (24-month retention on Premium), early-warning intrusion scans (8/day on Premium), remote plugin enable/disable. Plus on the agency side: single sign-on that provisions your team as admin users across every managed site at once (their words: add users in Watchful's SSO area to give them access to all your sites, which is a different thing from SAML login into Watchful itself), an agency dashboard for managing multiple client sites, blacklist scanning, broken-link checking inside their SEO audit, API access for custom workflows, and a free tier covering smaller agencies. SiteLetter does not run WordPress or Joomla maintenance and does not ship security scanning.
Cross-platform monitoring: any website stack including Webflow, Framer, Squarespace, Shopify, custom builds (Watchful is WordPress and Joomla only). Per-page Google Lighthouse on every monitored page daily with DNS/TLS/CDN cache warmup (Watchful has uptime + performance probes but no Lighthouse four-score breakdown per monitored page). AI day-over-day visual regression that classifies each diff big enough to matter as noise / intentional / breakage (Watchful is CMS-aware monitoring, not a continuous classified visual diff across every monitored page). Sitemap auto-discovery: add a domain, SiteLetter picks the 15 most important pages and every monitor turns on for them (Watchful operates inside the CMS install). Branded scheduled per-client email reports with per-client logo, brand color, reply-to.
Yes if you are moving toward cross-platform work or you need deeper per-page monitoring, but read this carefully: SiteLetter does not replace WordPress/Joomla maintenance. If you are leaving Watchful for SiteLetter without keeping another maintenance tool, your WordPress and Joomla clients lose update management, backups, and security scanning. The honest move for mixed-stack agencies is to keep Watchful (or similar) for WP/Joomla maintenance and add SiteLetter for the cross-platform monitoring and deeper reporting on top. New accounts get 14 days of full monitoring on one site with no card, so add one of your non-WP/Joomla client sites to validate the cross-platform experience before extending.
Yes. Watchful handles CMS-side maintenance (updates, backups, security scanning, plugin management) on the WordPress and Joomla sites in your portfolio. SiteLetter handles the modern monitoring layer (uptime, Lighthouse, AI visual regression, broken assets) plus the branded weekly client report across the whole portfolio, including the non-WP sites. The two layers are different jobs done by different tools. That said, if you want to consolidate, the SiteLetter wedge is that one tool covers monitoring + report for every site you bill for, regardless of stack.
It is a fair signal of stability. Watchful has been operating for over a decade as a WordPress and Joomla maintenance platform with a loyal agency user base. SiteLetter is a newer focused product (launched 2026) built around modern monitoring shape: per-page Lighthouse with cache warmup, AI day-over-day visual classification, and per-tenant branded scheduled client reports - the features that did not exist in monitoring software a decade ago. Tenure matters for trust; the modern monitoring layer matters for what you can ship to a client today. The right answer depends on which you weight more.
Still have questions? Get in touch.
Comparison based on publicly available Watchful feature documentation, last verified . Pricing was read separately from their pricing page on , which is the date the per-install figure on this page carries. Watchful 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 Watchful. For the most current Watchful pricing and feature information, see watchful.net.
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.