diff --git a/PROGRESS.md b/PROGRESS.md
index 6c7e05a..3d5acdc 100644
--- a/PROGRESS.md
+++ b/PROGRESS.md
@@ -22,6 +22,7 @@
 - Denormalized product fields (cheapest_price, in_stock, on_sale) for DB-level sort/filter
 - Transactional emails (order confirmation, shipping notification)
 - Demo content polished and ready for production
+- Privacy-first analytics with comparison mode (period deltas on stat cards)
 
 **Tier 1 MVP complete.** CI pipeline done. Hosting & deployment done (including observability). PageSpeed CI done (99-100 mobile, 97+ desktop). Usability fixes done. Shipping costs at checkout done. Per-colour product images with gallery filtering done (both providers). Printful integration complete (sync, orders, shipping, webhooks, mockup enrichment, catalog colours). CSS migration Phases 0-7 complete — project is fully Tailwind-free (hand-written CSS, 9.8 KB gzipped shop, 17.8 KB gzipped admin). Setup and launch readiness complete — `/setup` onboarding page, dashboard launch checklist, provider registry, provider-agnostic setup status.
 
@@ -87,7 +88,11 @@ Plans: [admin-redesign.md](docs/plans/admin-redesign.md) | [admin-font-loading.m
 | | **Bugs / polish** | | | |
 | ~~49~~ | ~~Admin font loading + cache miss path resolver ([plan](docs/plans/admin-font-loading.md))~~ | — | 1h | done |
 
-**All tasks complete.** No remaining work in the task list.
+| | **Analytics v2** ([plan](docs/plans/analytics-v2.md)) | | | |
+| ~~52~~ | ~~Comparison mode: period deltas on stat cards~~ | — | 1h | done |
+| 53 | Dashboard filtering (click to filter by dimension) | 52 | 3h | planned |
+| 54 | CSV export | 52 | 1.5h | planned |
+| 55 | Entry/exit pages panel | — | 1h | planned |
 
 See [css-migration.md](docs/plans/css-migration.md) for full plan with architecture, visual regression testing strategy, and acceptance criteria per phase.
 
@@ -114,7 +119,7 @@ Issues from hands-on testing of the deployed prod site (Feb 2025). 16 of 18 comp
 
 ### Tier 3 — Compliance & quality
 
-10. **Privacy-respecting analytics** — Self-hosted, cookie-free analytics. Plausible, Umami, or a lightweight custom solution. No Google Analytics, no third-party tracking. GDPR-friendly by design.
+10. ~~**Privacy-respecting analytics**~~ — ✅ In progress. Custom cookie-free analytics with pageviews, e-commerce funnel, device/browser/OS/country tracking. Period comparison deltas on stat cards. Next: dashboard filtering, CSV export, entry/exit pages.
 11. **AGPL licensing & code hosting** — Currently AGPL-3.0. Decide on GitHub vs Codeberg vs self-hosted Forgejo. Set up proper LICENSE file, contribution guidelines, and release process.
 12. **Security (Paraxial.io)** — Runtime application security monitoring for Elixir. Bot detection, rate limiting, vulnerability scanning. Evaluate whether it fits the self-hosted model.
 
@@ -374,7 +379,22 @@ See: [plan](docs/plans/shipping-sync.md) for implementation details
 - [x] `mix bench.sqlite` task with `--prod`, `--scale`, `--pool-size`, `--busy-timeout` options
 - [x] PRAGMA tuning across dev/test/prod: `default_transaction_mode: :immediate`, `journal_size_limit: 64MB`, `custom_pragmas: [mmap_size: 128MB]`
 - [x] Benchmarks confirmed: IMMEDIATE mode eliminates transaction upgrade BUSY errors (0% vs 73-80% failure rate under contention), prod mode 5-12x faster than dev, 300 concurrent mixed requests with zero errors
-- [x] 972 tests total (5 excluded: 3 benchmarks + 2 correctness)
+- [x] 1041 tests total (5 excluded: 3 benchmarks + 2 correctness)
+
+### Analytics
+**Status:** In progress (v2)
+
+- [x] Privacy-first, cookie-free analytics (2bd2e61)
+- [x] E-commerce funnel events: product_view, add_to_cart, checkout_start, purchase (f91b47f)
+- [x] Browser, OS, screen size collection (f91b47f)
+- [x] HTML/CSS bar chart with hourly today view and readable labels (08fcd60)
+- [x] Period comparison deltas on stat cards (6eda1de)
+- [x] 2-year demo seed data with growth curve (6eda1de)
+- [ ] Dashboard filtering (click referrer/country/device to filter all panels)
+- [ ] CSV export
+- [ ] Entry/exit pages panel
+
+See: [docs/plans/analytics-v2.md](docs/plans/analytics-v2.md) for v2 plan
 
 ### Page Editor
 **Status:** Future (Tier 4)
@@ -389,6 +409,8 @@ See: [docs/plans/page-builder.md](docs/plans/page-builder.md) for design
 
 | Feature | Commit | Notes |
 |---------|--------|-------|
+| Analytics comparison mode | 6eda1de | Period deltas on stat cards, 2-year seed data, zero-baseline handling, 1041 tests |
+| Analytics v1 + chart improvements | 2bd2e61..08fcd60 | Cookie-free analytics, e-commerce funnel, HTML/CSS bar chart, hourly today view |
 | Printify + Printful client tests | b0aed4c, a45e85e | Req.Test stubs for both HTTP clients, provider integration tests, mockup enricher tests, 972 tests |
 | SQLite production tuning | 162bf4c, 19d8c7d | Concurrency tests, `mix bench.sqlite` task, IMMEDIATE transactions, mmap 128MB, journal_size_limit 64MB, 898 tests |
 | Per-colour images + gallery filtering | 0fe48ba | colour column on product_images, per-colour mockup enrichment, PDP gallery filtering, Printify option filtering, hero colour ordering, 821 tests |
diff --git a/docs/plans/analytics-v2.md b/docs/plans/analytics-v2.md
index 6a3ff92..8a62069 100644
--- a/docs/plans/analytics-v2.md
+++ b/docs/plans/analytics-v2.md
@@ -1,23 +1,25 @@
 # Analytics dashboard v2
 
-Status: Planned
+Status: In progress
 
 ## Current state (v1)
 
 - Unique visitors, pageviews, bounce rate, visit duration
-- SVG bar chart for visitor trends
+- HTML/CSS bar chart with tooltip hover, hourly today view, readable labels
 - Date range picker (Today, 7d, 30d, 12m)
 - Top pages, sources/referrers, countries, devices
 - E-commerce conversion funnel (product view → cart → checkout → purchase)
 - Data collection: UTMs, referrers, browser, OS, screen size, full e-commerce funnel
+- Period comparison deltas on stat cards (↑12%, ↓3%)
+- Demo seed data spanning 2 years for meaningful comparisons
 
 ## Improvements (priority order)
 
 ### 1. Comparison mode
 
-Compare current period vs previous period. Show deltas on each metric (↑12%, ↓3%). Already have date ranges — just query the previous period in parallel and render the difference. Low effort, high value.
+~~Compare current period vs previous period.~~ Done (6eda1de). Each stat card shows percentage delta vs equivalent previous period. Handles zero-baseline (shows "new"), caps extreme deltas at >999%. Bounce rate uses inverted colour logic (lower = green). Seed data extended to 2 years.
 
-**Files:** `lib/berrypod/analytics.ex` (queries), `lib/berrypod_web/live/admin/analytics.ex` (UI)
+**Files:** `lib/berrypod_web/live/admin/analytics.ex` (date range calc, delta display), `priv/repo/seeds/analytics.exs` (2-year data)
 
 ### 2. Dashboard filtering
 
diff --git a/lib/berrypod/analytics.ex b/lib/berrypod/analytics.ex
index 84dffde..7e49431 100644
--- a/lib/berrypod/analytics.ex
+++ b/lib/berrypod/analytics.ex
@@ -56,8 +56,8 @@ defmodule Berrypod.Analytics do
   @doc """
   Counts unique visitors in the given date range.
   """
-  def count_visitors(date_range) do
-    base_query(date_range)
+  def count_visitors(date_range, filters \\ %{}) do
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> select([e], count(e.visitor_hash, :distinct))
     |> Repo.one()
@@ -66,8 +66,8 @@ defmodule Berrypod.Analytics do
   @doc """
   Counts total pageviews in the given date range.
   """
-  def count_pageviews(date_range) do
-    base_query(date_range)
+  def count_pageviews(date_range, filters \\ %{}) do
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> select([e], count())
     |> Repo.one()
@@ -78,9 +78,9 @@ defmodule Berrypod.Analytics do
 
   Bounce = a session with only one pageview.
   """
-  def bounce_rate(date_range) do
+  def bounce_rate(date_range, filters \\ %{}) do
     sessions_query =
-      base_query(date_range)
+      base_query(date_range, filters)
       |> where([e], e.name == "pageview")
       |> group_by([e], e.session_hash)
       |> select([e], %{
@@ -107,9 +107,9 @@ defmodule Berrypod.Analytics do
   @doc """
   Average visit duration in seconds.
   """
-  def avg_duration(date_range) do
+  def avg_duration(date_range, filters \\ %{}) do
     durations_query =
-      base_query(date_range)
+      base_query(date_range, filters)
       |> where([e], e.name == "pageview")
       |> group_by([e], e.session_hash)
       |> having([e], count() > 1)
@@ -136,8 +136,8 @@ defmodule Berrypod.Analytics do
 
   Returns a list of `%{date: ~D[], visitors: integer}` maps.
   """
-  def visitors_by_date(date_range) do
-    base_query(date_range)
+  def visitors_by_date(date_range, filters \\ %{}) do
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> group_by([e], fragment("date(?)", e.inserted_at))
     |> select([e], %{
@@ -153,9 +153,9 @@ defmodule Berrypod.Analytics do
 
   Returns a list of `%{hour: integer, visitors: integer}` maps for all 24 hours.
   """
-  def visitors_by_hour(date_range) do
+  def visitors_by_hour(date_range, filters \\ %{}) do
     counts =
-      base_query(date_range)
+      base_query(date_range, filters)
       |> where([e], e.name == "pageview")
       |> group_by([e], fragment("CAST(strftime('%H', ?) AS INTEGER)", e.inserted_at))
       |> select([e], %{
@@ -174,8 +174,11 @@ defmodule Berrypod.Analytics do
   @doc """
   Top pages by unique visitors.
   """
-  def top_pages(date_range, limit \\ 10) do
-    base_query(date_range)
+  def top_pages(date_range, opts \\ []) do
+    limit = Keyword.get(opts, :limit, 10)
+    filters = Keyword.get(opts, :filters, %{})
+
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> group_by([e], e.pathname)
     |> select([e], %{
@@ -191,8 +194,11 @@ defmodule Berrypod.Analytics do
   @doc """
   Top referrer sources by unique visitors.
   """
-  def top_sources(date_range, limit \\ 10) do
-    base_query(date_range)
+  def top_sources(date_range, opts \\ []) do
+    limit = Keyword.get(opts, :limit, 10)
+    filters = Keyword.get(opts, :filters, %{})
+
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> where([e], not is_nil(e.referrer_source))
     |> group_by([e], e.referrer_source)
@@ -208,8 +214,11 @@ defmodule Berrypod.Analytics do
   @doc """
   Top referrer domains by unique visitors.
   """
-  def top_referrers(date_range, limit \\ 10) do
-    base_query(date_range)
+  def top_referrers(date_range, opts \\ []) do
+    limit = Keyword.get(opts, :limit, 10)
+    filters = Keyword.get(opts, :filters, %{})
+
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> where([e], not is_nil(e.referrer))
     |> group_by([e], e.referrer)
@@ -225,8 +234,11 @@ defmodule Berrypod.Analytics do
   @doc """
   Country breakdown by unique visitors.
   """
-  def top_countries(date_range, limit \\ 10) do
-    base_query(date_range)
+  def top_countries(date_range, opts \\ []) do
+    limit = Keyword.get(opts, :limit, 10)
+    filters = Keyword.get(opts, :filters, %{})
+
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> where([e], not is_nil(e.country_code))
     |> group_by([e], e.country_code)
@@ -242,10 +254,11 @@ defmodule Berrypod.Analytics do
   @doc """
   Device breakdown by the given dimension (:browser, :os, or :screen_size).
   """
-  def device_breakdown(date_range, dimension) when dimension in [:browser, :os, :screen_size] do
+  def device_breakdown(date_range, dimension, filters \\ %{})
+      when dimension in [:browser, :os, :screen_size] do
     field = dimension
 
-    base_query(date_range)
+    base_query(date_range, filters)
     |> where([e], e.name == "pageview")
     |> where([e], not is_nil(field(e, ^field)))
     |> group_by([e], field(e, ^field))
@@ -262,9 +275,9 @@ defmodule Berrypod.Analytics do
 
   Returns `%{product_views: n, add_to_carts: n, checkouts: n, purchases: n}`.
   """
-  def funnel(date_range) do
+  def funnel(date_range, filters \\ %{}) do
     counts =
-      base_query(date_range)
+      base_query(date_range, filters)
       |> where([e], e.name in ["product_view", "add_to_cart", "checkout_start", "purchase"])
       |> group_by([e], e.name)
       |> select([e], {e.name, count(e.visitor_hash, :distinct)})
@@ -282,8 +295,8 @@ defmodule Berrypod.Analytics do
   @doc """
   Total revenue in the given date range (pence).
   """
-  def total_revenue(date_range) do
-    base_query(date_range)
+  def total_revenue(date_range, filters \\ %{}) do
+    base_query(date_range, filters)
     |> where([e], e.name == "purchase")
     |> select([e], coalesce(sum(e.revenue), 0))
     |> Repo.one()
@@ -299,9 +312,24 @@ defmodule Berrypod.Analytics do
 
   # ── Private ──
 
-  defp base_query({start_date, end_date}) do
+  defp base_query({start_date, end_date}, filters) do
     from(e in Event,
       where: e.inserted_at >= ^start_date and e.inserted_at < ^end_date
     )
+    |> apply_filters(filters)
+  end
+
+  defp apply_filters(query, filters) when map_size(filters) == 0, do: query
+
+  defp apply_filters(query, filters) do
+    Enum.reduce(filters, query, fn
+      {:pathname, v}, q -> where(q, [e], e.pathname == ^v)
+      {:referrer_source, v}, q -> where(q, [e], e.referrer_source == ^v)
+      {:country_code, v}, q -> where(q, [e], e.country_code == ^v)
+      {:browser, v}, q -> where(q, [e], e.browser == ^v)
+      {:os, v}, q -> where(q, [e], e.os == ^v)
+      {:screen_size, v}, q -> where(q, [e], e.screen_size == ^v)
+      _, q -> q
+    end)
   end
 end
diff --git a/lib/berrypod_web/live/admin/analytics.ex b/lib/berrypod_web/live/admin/analytics.ex
index b018eed..5347a2d 100644
--- a/lib/berrypod_web/live/admin/analytics.ex
+++ b/lib/berrypod_web/live/admin/analytics.ex
@@ -11,6 +11,8 @@ defmodule BerrypodWeb.Admin.Analytics do
     "12m" => 364
   }
 
+  @filterable_dimensions ~w(pathname referrer_source country_code browser os screen_size)
+
   @impl true
   def mount(_params, _session, socket) do
     {:ok,
@@ -18,6 +20,7 @@ defmodule BerrypodWeb.Admin.Analytics do
      |> assign(:page_title, "Analytics")
      |> assign(:period, "30d")
      |> assign(:tab, "pages")
+     |> assign(:filters, %{})
      |> load_analytics("30d")}
   end
 
@@ -35,26 +38,54 @@ defmodule BerrypodWeb.Admin.Analytics do
     {:noreply, assign(socket, :tab, tab)}
   end
 
+  def handle_event("add_filter", %{"dimension" => dim, "value" => val}, socket)
+      when dim in @filterable_dimensions do
+    filters = Map.put(socket.assigns.filters, String.to_existing_atom(dim), val)
+
+    {:noreply,
+     socket
+     |> assign(:filters, filters)
+     |> load_analytics(socket.assigns.period)}
+  end
+
+  def handle_event("remove_filter", %{"dimension" => dim}, socket)
+      when dim in @filterable_dimensions do
+    filters = Map.delete(socket.assigns.filters, String.to_existing_atom(dim))
+
+    {:noreply,
+     socket
+     |> assign(:filters, filters)
+     |> load_analytics(socket.assigns.period)}
+  end
+
+  def handle_event("clear_filters", _params, socket) do
+    {:noreply,
+     socket
+     |> assign(:filters, %{})
+     |> load_analytics(socket.assigns.period)}
+  end
+
   # ── Data loading ──
 
   defp load_analytics(socket, period) do
     range = date_range(period)
     prev_range = previous_date_range(period)
+    filters = socket.assigns.filters
 
     trend_data =
       if period == "today",
-        do: Analytics.visitors_by_hour(range),
-        else: Analytics.visitors_by_date(range)
+        do: Analytics.visitors_by_hour(range, filters),
+        else: Analytics.visitors_by_date(range, filters)
 
-    visitors = Analytics.count_visitors(range)
-    pageviews = Analytics.count_pageviews(range)
-    bounce_rate = Analytics.bounce_rate(range)
-    avg_duration = Analytics.avg_duration(range)
+    visitors = Analytics.count_visitors(range, filters)
+    pageviews = Analytics.count_pageviews(range, filters)
+    bounce_rate = Analytics.bounce_rate(range, filters)
+    avg_duration = Analytics.avg_duration(range, filters)
 
-    prev_visitors = Analytics.count_visitors(prev_range)
-    prev_pageviews = Analytics.count_pageviews(prev_range)
-    prev_bounce_rate = Analytics.bounce_rate(prev_range)
-    prev_avg_duration = Analytics.avg_duration(prev_range)
+    prev_visitors = Analytics.count_visitors(prev_range, filters)
+    prev_pageviews = Analytics.count_pageviews(prev_range, filters)
+    prev_bounce_rate = Analytics.bounce_rate(prev_range, filters)
+    prev_avg_duration = Analytics.avg_duration(prev_range, filters)
 
     socket
     |> assign(:visitors, visitors)
@@ -67,15 +98,15 @@ defmodule BerrypodWeb.Admin.Analytics do
     |> assign(:avg_duration_delta, compute_delta(avg_duration, prev_avg_duration))
     |> assign(:trend_data, trend_data)
     |> assign(:trend_mode, if(period == "today", do: :hourly, else: :daily))
-    |> assign(:top_pages, Analytics.top_pages(range))
-    |> assign(:top_sources, Analytics.top_sources(range))
-    |> assign(:top_referrers, Analytics.top_referrers(range))
-    |> assign(:top_countries, Analytics.top_countries(range))
-    |> assign(:browsers, Analytics.device_breakdown(range, :browser))
-    |> assign(:oses, Analytics.device_breakdown(range, :os))
-    |> assign(:screen_sizes, Analytics.device_breakdown(range, :screen_size))
-    |> assign(:funnel, Analytics.funnel(range))
-    |> assign(:revenue, Analytics.total_revenue(range))
+    |> assign(:top_pages, Analytics.top_pages(range, filters: filters))
+    |> assign(:top_sources, Analytics.top_sources(range, filters: filters))
+    |> assign(:top_referrers, Analytics.top_referrers(range, filters: filters))
+    |> assign(:top_countries, Analytics.top_countries(range, filters: filters))
+    |> assign(:browsers, Analytics.device_breakdown(range, :browser, filters))
+    |> assign(:oses, Analytics.device_breakdown(range, :os, filters))
+    |> assign(:screen_sizes, Analytics.device_breakdown(range, :screen_size, filters))
+    |> assign(:funnel, Analytics.funnel(range, filters))
+    |> assign(:revenue, Analytics.total_revenue(range, filters))
   end
 
   defp date_range(period) do
@@ -122,6 +153,27 @@ defmodule BerrypodWeb.Admin.Analytics do
       </button>
     </div>
 
+    <%!-- Active filters --%>
+    <div
+      :if={@filters != %{}}
+      id="analytics-filters"
+      style="display: flex; gap: 0.5rem; flex-wrap: wrap; align-items: center; margin-top: 1rem;"
+    >
+      <.filter_chip
+        :for={{dim, val} <- @filters}
+        dimension={dim}
+        value={val}
+      />
+      <button
+        :if={map_size(@filters) > 1}
+        phx-click="clear_filters"
+        class="admin-btn admin-btn-sm"
+        style="font-size: 0.75rem;"
+      >
+        Clear all
+      </button>
+    </div>
+
     <%!-- Stat cards --%>
     <div class="admin-stats-grid" style="margin-top: 1.5rem;">
       <.stat_card
@@ -245,6 +297,36 @@ defmodule BerrypodWeb.Admin.Analytics do
     """
   end
 
+  # ── Filter chip ──
+
+  attr :dimension, :atom, required: true
+  attr :value, :string, required: true
+
+  defp filter_chip(assigns) do
+    assigns = assign(assigns, label: filter_label(assigns.dimension, assigns.value))
+
+    ~H"""
+    <span style="display: inline-flex; align-items: center; gap: 0.25rem; padding: 0.25rem 0.5rem; font-size: 0.75rem; background: var(--color-base-200, #e5e5e5); border-radius: 0.25rem;">
+      {@label}
+      <button
+        phx-click="remove_filter"
+        phx-value-dimension={@dimension}
+        style="cursor: pointer; opacity: 0.6; line-height: 1;"
+        aria-label={"Remove #{@label} filter"}
+      >
+        <.icon name="hero-x-mark" class="size-3" />
+      </button>
+    </span>
+    """
+  end
+
+  defp filter_label(:pathname, val), do: "Page: #{val}"
+  defp filter_label(:referrer_source, val), do: "Source: #{val}"
+  defp filter_label(:country_code, val), do: "Country: #{country_name(val)}"
+  defp filter_label(:browser, val), do: "Browser: #{val}"
+  defp filter_label(:os, val), do: "OS: #{val}"
+  defp filter_label(:screen_size, val), do: "Screen: #{val}"
+
   # ── Bar chart (HTML/CSS bars with readable labels) ──
 
   attr :data, :list, required: true
@@ -421,7 +503,7 @@ defmodule BerrypodWeb.Admin.Analytics do
       rows={@top_pages}
       empty_message="No page data yet"
       columns={[
-        %{label: "Page", key: :pathname},
+        %{label: "Page", key: :pathname, filter: {:pathname, :pathname}},
         %{label: "Visitors", key: :visitors, align: :right},
         %{label: "Pageviews", key: :pageviews, align: :right}
       ]}
@@ -436,7 +518,7 @@ defmodule BerrypodWeb.Admin.Analytics do
       rows={@top_sources}
       empty_message="No referrer data yet"
       columns={[
-        %{label: "Source", key: :source},
+        %{label: "Source", key: :source, filter: {:referrer_source, :source}},
         %{label: "Visitors", key: :visitors, align: :right}
       ]}
     />
@@ -453,13 +535,20 @@ defmodule BerrypodWeb.Admin.Analytics do
   end
 
   defp tab_content(%{tab: "countries"} = assigns) do
+    rows =
+      Enum.map(assigns.top_countries, fn c ->
+        Map.put(c, :display_name, country_name(c.country_code))
+      end)
+
+    assigns = assign(assigns, :country_rows, rows)
+
     ~H"""
     <h3 style="font-size: 0.875rem; font-weight: 600; margin-bottom: 0.75rem;">Countries</h3>
     <.detail_table
-      rows={Enum.map(@top_countries, fn c -> %{c | country_code: country_name(c.country_code)} end)}
+      rows={@country_rows}
       empty_message="No country data yet"
       columns={[
-        %{label: "Country", key: :country_code},
+        %{label: "Country", key: :display_name, filter: {:country_code, :country_code}},
         %{label: "Visitors", key: :visitors, align: :right}
       ]}
     />
@@ -473,7 +562,7 @@ defmodule BerrypodWeb.Admin.Analytics do
       rows={@browsers}
       empty_message="No browser data yet"
       columns={[
-        %{label: "Browser", key: :name},
+        %{label: "Browser", key: :name, filter: {:browser, :name}},
         %{label: "Visitors", key: :visitors, align: :right}
       ]}
     />
@@ -484,7 +573,7 @@ defmodule BerrypodWeb.Admin.Analytics do
       rows={@oses}
       empty_message="No OS data yet"
       columns={[
-        %{label: "OS", key: :name},
+        %{label: "OS", key: :name, filter: {:os, :name}},
         %{label: "Visitors", key: :visitors, align: :right}
       ]}
     />
@@ -493,7 +582,7 @@ defmodule BerrypodWeb.Admin.Analytics do
       rows={@screen_sizes}
       empty_message="No screen data yet"
       columns={[
-        %{label: "Size", key: :name},
+        %{label: "Size", key: :name, filter: {:screen_size, :name}},
         %{label: "Visitors", key: :visitors, align: :right}
       ]}
     />
@@ -540,7 +629,19 @@ defmodule BerrypodWeb.Admin.Analytics do
             :for={col <- @columns}
             style={col[:align] == :right && "text-align: right; font-variant-numeric: tabular-nums;"}
           >
-            {Map.get(row, col.key)}
+            <%= if col[:filter] do %>
+              <span
+                class="admin-link"
+                style="cursor: pointer;"
+                phx-click="add_filter"
+                phx-value-dimension={elem(col.filter, 0)}
+                phx-value-value={Map.get(row, elem(col.filter, 1))}
+              >
+                {Map.get(row, col.key)}
+              </span>
+            <% else %>
+              {Map.get(row, col.key)}
+            <% end %>
           </td>
         </tr>
       </tbody>
diff --git a/test/berrypod/analytics_test.exs b/test/berrypod/analytics_test.exs
index 62da370..fe6646a 100644
--- a/test/berrypod/analytics_test.exs
+++ b/test/berrypod/analytics_test.exs
@@ -231,6 +231,62 @@ defmodule Berrypod.AnalyticsTest do
     end
   end
 
+  describe "filtering" do
+    test "count_visitors respects country_code filter" do
+      v1 = :crypto.strong_rand_bytes(8)
+      v2 = :crypto.strong_rand_bytes(8)
+
+      insert_event(%{visitor_hash: v1, country_code: "GB"})
+      insert_event(%{visitor_hash: v2, country_code: "US"})
+
+      assert Analytics.count_visitors(today_range(), %{country_code: "GB"}) == 1
+    end
+
+    test "top_pages respects referrer_source filter" do
+      v1 = :crypto.strong_rand_bytes(8)
+      v2 = :crypto.strong_rand_bytes(8)
+
+      insert_event(%{visitor_hash: v1, pathname: "/", referrer_source: "Google"})
+      insert_event(%{visitor_hash: v2, pathname: "/about", referrer_source: "Facebook"})
+
+      pages = Analytics.top_pages(today_range(), filters: %{referrer_source: "Google"})
+      assert length(pages) == 1
+      assert hd(pages).pathname == "/"
+    end
+
+    test "bounce_rate respects filter" do
+      s1 = :crypto.strong_rand_bytes(8)
+      s2 = :crypto.strong_rand_bytes(8)
+
+      # GB visitor bounces (1 pageview)
+      insert_event(%{session_hash: s1, country_code: "GB"})
+      # US visitor doesn't bounce (2 pageviews)
+      insert_event(%{session_hash: s2, country_code: "US", pathname: "/"})
+      insert_event(%{session_hash: s2, country_code: "US", pathname: "/about"})
+
+      assert Analytics.bounce_rate(today_range(), %{country_code: "GB"}) == 100
+      assert Analytics.bounce_rate(today_range(), %{country_code: "US"}) == 0
+    end
+
+    test "multiple filters combine with AND logic" do
+      v1 = :crypto.strong_rand_bytes(8)
+      v2 = :crypto.strong_rand_bytes(8)
+
+      insert_event(%{visitor_hash: v1, country_code: "GB", browser: "Chrome"})
+      insert_event(%{visitor_hash: v2, country_code: "GB", browser: "Firefox"})
+
+      assert Analytics.count_visitors(today_range(), %{country_code: "GB", browser: "Chrome"}) ==
+               1
+    end
+
+    test "unknown filter keys are ignored" do
+      v1 = :crypto.strong_rand_bytes(8)
+      insert_event(%{visitor_hash: v1})
+
+      assert Analytics.count_visitors(today_range(), %{nonexistent: "val"}) == 1
+    end
+  end
+
   describe "delete_events_before/1" do
     test "deletes old events" do
       old = DateTime.add(DateTime.utc_now(), -400, :day) |> DateTime.truncate(:second)
diff --git a/test/berrypod_web/live/admin/analytics_test.exs b/test/berrypod_web/live/admin/analytics_test.exs
index 67a6836..323d6a5 100644
--- a/test/berrypod_web/live/admin/analytics_test.exs
+++ b/test/berrypod_web/live/admin/analytics_test.exs
@@ -102,5 +102,63 @@ defmodule BerrypodWeb.Admin.AnalyticsTest do
       html = render_click(view, "change_tab", %{"tab" => "funnel"})
       assert html =~ "Conversion funnel"
     end
+
+    test "clicking a source adds a filter chip", %{conn: conn} do
+      now = DateTime.utc_now() |> DateTime.truncate(:second)
+
+      Repo.insert_all(Event, [
+        [
+          id: Ecto.UUID.generate(),
+          name: "pageview",
+          pathname: "/",
+          visitor_hash: :crypto.strong_rand_bytes(8),
+          session_hash: :crypto.strong_rand_bytes(8),
+          referrer_source: "Google",
+          inserted_at: now
+        ]
+      ])
+
+      {:ok, view, _html} = live(conn, ~p"/admin/analytics")
+
+      # Switch to sources tab and click the source
+      render_click(view, "change_tab", %{"tab" => "sources"})
+
+      html =
+        render_click(view, "add_filter", %{"dimension" => "referrer_source", "value" => "Google"})
+
+      assert html =~ "Source: Google"
+      assert has_element?(view, "#analytics-filters")
+    end
+
+    test "removing a filter chip clears it", %{conn: conn} do
+      {:ok, view, _html} = live(conn, ~p"/admin/analytics")
+
+      render_click(view, "add_filter", %{"dimension" => "country_code", "value" => "GB"})
+      assert render(view) =~ "Country: United Kingdom"
+
+      html = render_click(view, "remove_filter", %{"dimension" => "country_code"})
+      refute html =~ "Country: United Kingdom"
+    end
+
+    test "clear all removes all filters", %{conn: conn} do
+      {:ok, view, _html} = live(conn, ~p"/admin/analytics")
+
+      render_click(view, "add_filter", %{"dimension" => "country_code", "value" => "GB"})
+      render_click(view, "add_filter", %{"dimension" => "browser", "value" => "Chrome"})
+      assert render(view) =~ "Clear all"
+
+      html = render_click(view, "clear_filters", %{})
+      refute html =~ "Country: United Kingdom"
+      refute html =~ "Browser: Chrome"
+    end
+
+    test "changing period preserves filters", %{conn: conn} do
+      {:ok, view, _html} = live(conn, ~p"/admin/analytics")
+
+      render_click(view, "add_filter", %{"dimension" => "country_code", "value" => "GB"})
+      html = render_click(view, "change_period", %{"period" => "7d"})
+
+      assert html =~ "Country: United Kingdom"
+    end
   end
 end