diff --git a/src/lib/elements/element_manage_event_file_li.svelte b/src/lib/elements/element_manage_event_file_li.svelte
index 4aaa7094..3585a246 100644
--- a/src/lib/elements/element_manage_event_file_li.svelte
+++ b/src/lib/elements/element_manage_event_file_li.svelte
@@ -69,6 +69,53 @@
     });
 
     let clipboard_success = $state(false);
+
+    // PDF → Image conversion state (keyed by event_file_id)
+    // WHY: Poster sessions display files in the Launcher modal via <img> tag — PDFs can't render there.
+    // Presenters upload PDFs which must be converted server-side to high-res webp images.
+    // Button is only shown in edit_mode for PDF files linked to a poster-type session.
+    // Backend: /v3/action/hosted_file/{id}/convert_file runs pdf2image (3840px wide, first page only)
+    // and saves the result as a new hosted_file record linked to the same parent object.
+    type ConvertStatus = 'idle' | 'converting' | 'done' | 'error';
+    let convert_status_kv: Record<string, ConvertStatus> = $state({});
+    let convert_result_kv: key_val = $state({});
+
+    async function handle_convert_pdf_to_image(event_file_obj: key_val) {
+        const file_id = event_file_obj.event_file_id;
+        convert_status_kv[file_id] = 'converting';
+        try {
+            // Link the new image to the most specific parent available
+            const link_to_type_val = event_file_obj.event_session_id ? 'event_session'
+                : event_file_obj.event_presentation_id ? 'event_presentation'
+                : 'event';
+            const link_to_id_val = event_file_obj.event_session_id
+                || event_file_obj.event_presentation_id
+                || event_file_obj.event_id;
+            const filename_no_ext = (event_file_obj.filename ?? 'poster_image').replace(/\.pdf$/i, '');
+            const url = `${$ae_api.base_url}/v3/action/hosted_file/${event_file_obj.hosted_file_id}/convert_file`
+                + `?link_to_type=${encodeURIComponent(link_to_type_val)}`
+                + `&link_to_id=${encodeURIComponent(link_to_id_val)}`
+                + `&filename_no_ext=${encodeURIComponent(filename_no_ext)}`
+                + `&to_type=webp`;
+            const resp = await fetch(url, {
+                headers: {
+                    'x-aether-api-key': $ae_api.api_secret_key,
+                    'x-account-id': String($ae_api.account_id ?? '')
+                }
+            });
+            const body = await resp.json();
+            if (resp.ok && body?.data) {
+                convert_result_kv[file_id] = body.data;
+                convert_status_kv[file_id] = 'done';
+            } else {
+                console.error('[convert_pdf] API error:', body);
+                convert_status_kv[file_id] = 'error';
+            }
+        } catch (err) {
+            console.error('[convert_pdf] Fetch failed:', err);
+            convert_status_kv[file_id] = 'error';
+        }
+    }
 </script>
 
 <div class="float-right flex flex-row items-center">
@@ -191,6 +238,45 @@
                                             classes="btn btn-sm lg:btn-md preset-tonal-primary hover:preset-filled-primary-500 min-w-72 lg:min-w-96"
                                         />
 
+                                        <!-- PDF → webp convert button: only for poster sessions in edit mode -->
+                                        {#if $ae_loc.edit_mode && event_file_obj?.extension === 'pdf' && event_file_obj?.event_session_type_code === 'poster'}
+                                            <div>
+                                                {#if !convert_status_kv[event_file_obj.event_file_id] || convert_status_kv[event_file_obj.event_file_id] === 'idle'}
+                                                    <button
+                                                        type="button"
+                                                        class="btn btn-sm preset-tonal-warning border border-warning-500"
+                                                        title="Convert this PDF to a high-res webp image for use in the Launcher poster display."
+                                                        onclick={() => handle_convert_pdf_to_image(event_file_obj)}
+                                                    >
+                                                        <span class="fas fa-file-image mx-1"></span>
+                                                        Convert PDF → Image
+                                                    </button>
+                                                {:else if convert_status_kv[event_file_obj.event_file_id] === 'converting'}
+                                                    <span class="btn btn-sm preset-tonal-surface opacity-60 cursor-wait">
+                                                        <span class="fas fa-spinner fa-spin mx-1"></span>
+                                                        Converting…
+                                                    </span>
+                                                {:else if convert_status_kv[event_file_obj.event_file_id] === 'done'}
+                                                    <span class="btn btn-sm preset-tonal-success" title="Conversion complete. New webp hosted_file created: {convert_result_kv[event_file_obj.event_file_id]?.filename ?? ''}">
+                                                        <span class="fas fa-check mx-1"></span>
+                                                        Done — {convert_result_kv[event_file_obj.event_file_id]?.filename ?? 'image created'}
+                                                    </span>
+                                                {:else if convert_status_kv[event_file_obj.event_file_id] === 'error'}
+                                                    <button
+                                                        type="button"
+                                                        class="btn btn-sm preset-tonal-error border border-error-500"
+                                                        title="Conversion failed. Click to retry."
+                                                        onclick={() => {
+                                                            convert_status_kv[event_file_obj.event_file_id] = 'idle';
+                                                        }}
+                                                    >
+                                                        <span class="fas fa-exclamation-triangle mx-1"></span>
+                                                        Failed — Retry?
+                                                    </button>
+                                                {/if}
+                                            </div>
+                                        {/if}
+
                                         {#if ae_tmp.show__direct_download}
                                             <div
                                                 class="px-4 py-2 flex flex-col gap-0.5 bg-surface-100/50 rounded-lg border border-surface-500/10"