diff --git a/tools/ui/src/lib/services/models.service.ts b/tools/ui/src/lib/services/models.service.ts
index 0b337775f4..96902a0b9d 100644
--- a/tools/ui/src/lib/services/models.service.ts
+++ b/tools/ui/src/lib/services/models.service.ts
@@ -7,7 +7,7 @@
  */
 
 import { base } from '$app/paths';
-import { API_MODELS, MODEL_ID, type ModelSidecar, SIDECAR_TOKENS } from '$lib/constants';
+import { API_MODELS, MODEL_ID, type ModelSidecar } from '$lib/constants';
 import { ServerModelStatus } from '$lib/enums';
 import type { ParsedModelId } from '$lib/types/models';
 import {
@@ -17,6 +17,7 @@ import {
 	extractSseDataPayload,
 	normalizeModelName,
 	sidecarFromFileToken,
+	sidecarFromTag,
 	splitSseRecords
 } from '$lib/utils';
 import { getAuthHeaders } from '$lib/utils/api-headers';
@@ -94,11 +95,7 @@ export class ModelsService {
 
 		if (idx === MODEL_ID.NOT_FOUND) return false;
 
-		const tag = modelId.slice(idx + 1).toLowerCase();
-		const dash = tag.lastIndexOf(MODEL_ID.SEGMENT_SEPARATOR);
-		const token = dash === -1 ? tag : tag.slice(dash + 1);
-
-		return SIDECAR_TOKENS.includes(token);
+		return sidecarFromTag(modelId.slice(idx + 1)) !== null;
 	}
 
 	/**
diff --git a/tools/ui/src/lib/stores/models/status.svelte.ts b/tools/ui/src/lib/stores/models/status.svelte.ts
index ab237e5d8d..b0ac083664 100644
--- a/tools/ui/src/lib/stores/models/status.svelte.ts
+++ b/tools/ui/src/lib/stores/models/status.svelte.ts
@@ -169,8 +169,11 @@ export class ModelStatusManager {
 		// localStorage; the progress snapshot is stale after a reload and stays null
 		try {
 			const raw = localStorage.getItem(PAUSED_MODEL_DOWNLOADS_LOCALSTORAGE_KEY);
+			const parsed: unknown = JSON.parse(raw ?? '[]');
 
-			for (const repoWithTag of JSON.parse(raw ?? '[]') as string[]) {
+			if (!Array.isArray(parsed)) return;
+
+			for (const repoWithTag of parsed.filter((id): id is string => typeof id === 'string')) {
 				this.pausedDownloads.set(repoWithTag, null);
 			}
 		} catch {
diff --git a/tools/ui/src/lib/utils/index.ts b/tools/ui/src/lib/utils/index.ts
index 988a7a237e..21d84dc8d6 100644
--- a/tools/ui/src/lib/utils/index.ts
+++ b/tools/ui/src/lib/utils/index.ts
@@ -108,7 +108,7 @@ export {
 export { normalizeModelName, isValidModelName } from './model-names';
 
 // Sidecar token utilities
-export { isAuxSidecar, isDraftSidecar, sidecarFromFileToken } from './sidecars';
+export { isAuxSidecar, isDraftSidecar, sidecarFromFileToken, sidecarFromTag } from './sidecars';
 
 // Portal utilities
 export { portalToBody } from './portal-to-body';
diff --git a/tools/ui/src/lib/utils/sidecars.ts b/tools/ui/src/lib/utils/sidecars.ts
index a3eb3841fd..52532b135a 100644
--- a/tools/ui/src/lib/utils/sidecars.ts
+++ b/tools/ui/src/lib/utils/sidecars.ts
@@ -1,4 +1,4 @@
-import { type ModelSidecar, SIDECAR_TOKENS } from '$lib/constants';
+import { MODEL_ID, type ModelSidecar, SIDECAR_TOKENS } from '$lib/constants';
 import { ModelAuxSidecar, ModelDraftSidecar } from '$lib/enums';
 
 const SIDECAR_TOKEN_SET = new Set<string>(SIDECAR_TOKENS);
@@ -10,6 +10,17 @@ export function sidecarFromFileToken(token: string): ModelSidecar | null {
 	return SIDECAR_TOKEN_SET.has(token) ? (token as ModelSidecar) : null;
 }
 
+/**
+ * Sidecar a download tag points at: the segment after the last dash,
+ * e.g. `q4_0-mtp` -> `mtp`, `mmproj` -> `mmproj`. Returns null for quant-only
+ * tags and tags whose tail is not a sidecar token.
+ */
+export function sidecarFromTag(tag: string): ModelSidecar | null {
+	const token = tag.toLowerCase().split(MODEL_ID.SEGMENT_SEPARATOR).pop() ?? '';
+
+	return sidecarFromFileToken(token);
+}
+
 export function isDraftSidecar(sidecar: ModelSidecar): sidecar is ModelDraftSidecar {
 	return DRAFT_SIDECAR_SET.has(sidecar);
 }
diff --git a/tools/ui/tests/unit/model-sidecar-grammar.test.ts b/tools/ui/tests/unit/model-sidecar-grammar.test.ts
index eda2b5d62d..1ad59171a9 100644
--- a/tools/ui/tests/unit/model-sidecar-grammar.test.ts
+++ b/tools/ui/tests/unit/model-sidecar-grammar.test.ts
@@ -1,6 +1,7 @@
 import { ModelAuxSidecar, ModelDraftSidecar, SidecarForm } from '$lib/enums';
 import { HuggingFaceService } from '$lib/services/huggingface.service';
 import { ModelsService } from '$lib/services/models.service';
+import { sidecarFromTag } from '$lib/utils';
 import { describe, expect, it } from 'vitest';
 
 const { buildDownloadTag, isSidecarEntry } = ModelsService;
@@ -125,3 +126,15 @@ describe('isSidecarEntry', () => {
 		expect(isSidecarEntry('org/repo')).toBe(false);
 	});
 });
+
+describe('sidecarFromTag', () => {
+	it('reads the token after the last dash', () => {
+		expect(sidecarFromTag('Q4_0-mtp')).toBe(ModelDraftSidecar.MTP);
+		expect(sidecarFromTag('mmproj')).toBe(ModelAuxSidecar.MMPROJ);
+	});
+
+	it('returns null for quant-only and unrelated tags', () => {
+		expect(sidecarFromTag('Q4_K_XL')).toBeNull();
+		expect(sidecarFromTag('UD-Q4_K_XL')).toBeNull();
+	});
+});