diff --git a/studio/frontend/src/features/chat/api/chat-adapter.ts b/studio/frontend/src/features/chat/api/chat-adapter.ts
index d99a7a0de6..15ac416b1f 100644
--- a/studio/frontend/src/features/chat/api/chat-adapter.ts
+++ b/studio/frontend/src/features/chat/api/chat-adapter.ts
@@ -442,10 +442,12 @@ export function createOpenAIStreamAdapter(): ChatModelAdapter {
           Boolean(message),
         );
 
-      if (params.systemPrompt.trim()) {
+      const safeSystemPrompt =
+        typeof params.systemPrompt === "string" ? params.systemPrompt : "";
+      if (safeSystemPrompt.trim()) {
         outboundMessages.unshift({
           role: "system",
-          content: params.systemPrompt.trim(),
+          content: safeSystemPrompt.trim(),
         });
       }
       const imageBase64 = findLatestUserImageBase64(messages);
diff --git a/studio/frontend/src/features/chat/chat-settings-sheet.tsx b/studio/frontend/src/features/chat/chat-settings-sheet.tsx
index 5a25a1536e..45c9d17888 100644
--- a/studio/frontend/src/features/chat/chat-settings-sheet.tsx
+++ b/studio/frontend/src/features/chat/chat-settings-sheet.tsx
@@ -10,6 +10,16 @@ import {
 } from "@/components/ui/select";
 import { Slider } from "@/components/ui/slider";
 import { Textarea } from "@/components/ui/textarea";
+import { Input } from "@/components/ui/input";
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
 import {
   ArrowDown01Icon,
   CodeIcon,
@@ -30,7 +40,7 @@ import {
 } from "@/components/ui/sheet";
 import { useIsMobile } from "@/hooks/use-mobile";
 import type { ReactNode } from "react";
-import { useState } from "react";
+import { useEffect, useMemo, useState } from "react";
 import {
   DEFAULT_INFERENCE_PARAMS,
   type InferenceParams,
@@ -72,6 +82,52 @@ const BUILTIN_PRESETS: Preset[] = [
   },
 ];
 
+const CHAT_PRESETS_KEY = "unsloth_chat_custom_presets";
+const CHAT_ACTIVE_PRESET_KEY = "unsloth_chat_active_preset";
+
+function canUseStorage(): boolean {
+  return typeof window !== "undefined";
+}
+
+function loadSavedCustomPresets(): Preset[] {
+  if (!canUseStorage()) return [];
+  try {
+    const raw = localStorage.getItem(CHAT_PRESETS_KEY);
+    if (!raw) return [];
+    const parsed = JSON.parse(raw) as unknown;
+    if (!Array.isArray(parsed)) return [];
+    return parsed
+      .filter((item): item is Preset => {
+        if (!item || typeof item !== "object") return false;
+        const maybe = item as Partial<Preset>;
+        return typeof maybe.name === "string" && !!maybe.params;
+      })
+      .map((preset) => ({
+        name: preset.name.trim(),
+        params: {
+          ...defaultInferenceParams,
+          ...preset.params,
+        },
+      }))
+      .filter(
+        (preset) =>
+          preset.name.length > 0 &&
+          !BUILTIN_PRESETS.some((builtin) => builtin.name === preset.name),
+      );
+  } catch {
+    return [];
+  }
+}
+
+function loadSavedActivePreset(): string {
+  if (!canUseStorage()) return "Default";
+  try {
+    return localStorage.getItem(CHAT_ACTIVE_PRESET_KEY) ?? "Default";
+  } catch {
+    return "Default";
+  }
+}
+
 function ParamSlider({
   label,
   value,
@@ -181,8 +237,16 @@ export function ChatSettingsPanel({
   const ggufContextLength = useChatRuntimeStore((s) => s.ggufContextLength);
   const kvCacheDtype = useChatRuntimeStore((s) => s.kvCacheDtype);
   const setKvCacheDtype = useChatRuntimeStore((s) => s.setKvCacheDtype);
-  const [presets, setPresets] = useState<Preset[]>(BUILTIN_PRESETS);
-  const [activePreset, setActivePreset] = useState("Default");
+  const [customPresets, setCustomPresets] = useState<Preset[]>(() =>
+    loadSavedCustomPresets(),
+  );
+  const [activePreset, setActivePreset] = useState(() => loadSavedActivePreset());
+  const [savePresetOpen, setSavePresetOpen] = useState(false);
+  const [presetNameDraft, setPresetNameDraft] = useState("");
+  const presets = useMemo(
+    () => [...BUILTIN_PRESETS, ...customPresets],
+    [customPresets],
+  );
   const isBuiltinPreset = BUILTIN_PRESETS.some((p) => p.name === activePreset);
 
   function set<K extends keyof InferenceParams>(key: K) {
@@ -199,32 +263,93 @@ export function ChatSettingsPanel({
         trustRemoteCode: params.trustRemoteCode,
       });
       setActivePreset(name);
+      if (canUseStorage()) {
+        try {
+          localStorage.setItem(CHAT_ACTIVE_PRESET_KEY, name);
+        } catch {
+          // ignore
+        }
+      }
     }
   }
 
-  function savePreset() {
-    const name = prompt("Preset name:");
-    if (!name?.trim()) {
+  function openSavePresetDialog() {
+    setPresetNameDraft(activePreset === "Default" ? "" : activePreset);
+    setSavePresetOpen(true);
+  }
+
+  function savePresetWithName(rawName: string) {
+    const trimmed = rawName.trim();
+    if (!trimmed) {
       return;
     }
-    const trimmed = name.trim();
-    setPresets((prev) => [
-      ...prev.filter((p) => p.name !== trimmed),
-      { name: trimmed, params: { ...params } },
-    ]);
+    if (BUILTIN_PRESETS.some((preset) => preset.name === trimmed)) {
+      return;
+    }
+    setCustomPresets((prev) => {
+      const next = [
+        ...prev.filter((preset) => preset.name !== trimmed),
+        { name: trimmed, params: { ...params } },
+      ];
+      if (canUseStorage()) {
+        try {
+          localStorage.setItem(CHAT_PRESETS_KEY, JSON.stringify(next));
+        } catch {
+          // ignore
+        }
+      }
+      return next;
+    });
+    if (canUseStorage()) {
+      try {
+        localStorage.setItem(CHAT_ACTIVE_PRESET_KEY, trimmed);
+      } catch {
+        // ignore
+      }
+    }
     setActivePreset(trimmed);
+    setSavePresetOpen(false);
   }
 
   function deletePreset(name: string) {
     if (BUILTIN_PRESETS.some((p) => p.name === name)) {
       return;
     }
-    setPresets((prev) => prev.filter((p) => p.name !== name));
+    setCustomPresets((prev) => {
+      const next = prev.filter((preset) => preset.name !== name);
+      if (canUseStorage()) {
+        try {
+          localStorage.setItem(CHAT_PRESETS_KEY, JSON.stringify(next));
+        } catch {
+          // ignore
+        }
+      }
+      return next;
+    });
     if (activePreset === name) {
       setActivePreset("Default");
+      if (canUseStorage()) {
+        try {
+          localStorage.setItem(CHAT_ACTIVE_PRESET_KEY, "Default");
+        } catch {
+          // ignore
+        }
+      }
     }
   }
 
+  useEffect(() => {
+    if (presets.some((preset) => preset.name === activePreset)) return;
+    setActivePreset("Default");
+    if (canUseStorage()) {
+      try {
+        localStorage.setItem(CHAT_ACTIVE_PRESET_KEY, "Default");
+      } catch {
+        // ignore
+      }
+    }
+  }, [activePreset, presets]);
+
   const settingsContent = (
     <>
       <div className="flex items-center gap-2 px-4 py-3">
@@ -255,7 +380,7 @@ export function ChatSettingsPanel({
               </Select>
               <button
                 type="button"
-                onClick={savePreset}
+                onClick={openSavePresetDialog}
                 className="flex h-8 items-center gap-1.5 rounded-md border px-2.5 text-xs text-muted-foreground transition-colors hover:bg-accent"
                 title="Save preset"
               >
@@ -442,6 +567,51 @@ export function ChatSettingsPanel({
 
           <ChatTemplateSection onReloadModel={onReloadModel} />
         </div>
+        <Dialog
+          open={savePresetOpen}
+          onOpenChange={(nextOpen) => {
+            setSavePresetOpen(nextOpen);
+            if (!nextOpen) {
+              setPresetNameDraft("");
+            }
+          }}
+        >
+          <DialogContent className="corner-squircle sm:max-w-sm">
+            <DialogHeader>
+              <DialogTitle>Save Preset</DialogTitle>
+              <DialogDescription>
+                Enter a name for this inference preset.
+              </DialogDescription>
+            </DialogHeader>
+            <form
+              onSubmit={(event) => {
+                event.preventDefault();
+                savePresetWithName(presetNameDraft);
+              }}
+              className="space-y-4"
+            >
+              <Input
+                autoFocus={true}
+                value={presetNameDraft}
+                onChange={(event) => setPresetNameDraft(event.target.value)}
+                placeholder="Preset name"
+                maxLength={80}
+              />
+              <DialogFooter>
+                <Button
+                  type="button"
+                  variant="outline"
+                  onClick={() => setSavePresetOpen(false)}
+                >
+                  Cancel
+                </Button>
+                <Button type="submit" disabled={presetNameDraft.trim().length === 0}>
+                  Save
+                </Button>
+              </DialogFooter>
+            </form>
+          </DialogContent>
+        </Dialog>
       </>
   );
 
diff --git a/studio/frontend/src/features/chat/stores/chat-runtime-store.ts b/studio/frontend/src/features/chat/stores/chat-runtime-store.ts
index fea5442187..920737a279 100644
--- a/studio/frontend/src/features/chat/stores/chat-runtime-store.ts
+++ b/studio/frontend/src/features/chat/stores/chat-runtime-store.ts
@@ -2,6 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { create } from "zustand";
+import { toast } from "sonner";
 import {
   DEFAULT_INFERENCE_PARAMS,
   type ChatLoraSummary,
@@ -13,6 +14,8 @@ const AUTO_TITLE_KEY = "unsloth_chat_auto_title";
 const AUTO_HEAL_TOOL_CALLS_KEY = "unsloth_auto_heal_tool_calls";
 const MAX_TOOL_CALLS_KEY = "unsloth_max_tool_calls_per_message";
 const TOOL_CALL_TIMEOUT_KEY = "unsloth_tool_call_timeout";
+const INFERENCE_PARAMS_KEY = "unsloth_chat_inference_params";
+let hasShownInferencePersistenceWarning = false;
 
 function canUseStorage(): boolean {
   return typeof window !== "undefined";
@@ -59,6 +62,65 @@ function saveInt(key: string, value: number): void {
   }
 }
 
+function asFiniteNumber(value: unknown, fallback: number): number {
+  return typeof value === "number" && Number.isFinite(value) ? value : fallback;
+}
+
+function asString(value: unknown, fallback: string): string {
+  return typeof value === "string" ? value : fallback;
+}
+
+function asBoolean(value: unknown, fallback: boolean): boolean {
+  return typeof value === "boolean" ? value : fallback;
+}
+
+function loadInferenceParams(): InferenceParams {
+  if (!canUseStorage()) return DEFAULT_INFERENCE_PARAMS;
+  try {
+    const raw = localStorage.getItem(INFERENCE_PARAMS_KEY);
+    if (!raw) return DEFAULT_INFERENCE_PARAMS;
+    const parsed = JSON.parse(raw) as Partial<InferenceParams>;
+    return {
+      temperature: asFiniteNumber(parsed.temperature, DEFAULT_INFERENCE_PARAMS.temperature),
+      topP: asFiniteNumber(parsed.topP, DEFAULT_INFERENCE_PARAMS.topP),
+      topK: asFiniteNumber(parsed.topK, DEFAULT_INFERENCE_PARAMS.topK),
+      minP: asFiniteNumber(parsed.minP, DEFAULT_INFERENCE_PARAMS.minP),
+      repetitionPenalty: asFiniteNumber(
+        parsed.repetitionPenalty,
+        DEFAULT_INFERENCE_PARAMS.repetitionPenalty,
+      ),
+      presencePenalty: asFiniteNumber(
+        parsed.presencePenalty,
+        DEFAULT_INFERENCE_PARAMS.presencePenalty,
+      ),
+      maxSeqLength: asFiniteNumber(
+        parsed.maxSeqLength,
+        DEFAULT_INFERENCE_PARAMS.maxSeqLength,
+      ),
+      maxTokens: asFiniteNumber(parsed.maxTokens, DEFAULT_INFERENCE_PARAMS.maxTokens),
+      systemPrompt: asString(parsed.systemPrompt, DEFAULT_INFERENCE_PARAMS.systemPrompt),
+      checkpoint: DEFAULT_INFERENCE_PARAMS.checkpoint,
+      trustRemoteCode: asBoolean(
+        parsed.trustRemoteCode,
+        DEFAULT_INFERENCE_PARAMS.trustRemoteCode ?? false,
+      ),
+    };
+  } catch {
+    return DEFAULT_INFERENCE_PARAMS;
+  }
+}
+
+function saveInferenceParams(params: InferenceParams): boolean {
+  if (!canUseStorage()) return false;
+  try {
+    const { checkpoint: _, ...rest } = params;
+    localStorage.setItem(INFERENCE_PARAMS_KEY, JSON.stringify(rest));
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 type ChatRuntimeStore = {
   params: InferenceParams;
   models: ChatModelSummary[];
@@ -117,7 +179,7 @@ type ChatRuntimeStore = {
 };
 
 export const useChatRuntimeStore = create<ChatRuntimeStore>((set) => ({
-  params: DEFAULT_INFERENCE_PARAMS,
+  params: loadInferenceParams(),
   models: [],
   loras: [],
   runningByThreadId: {},
@@ -144,7 +206,18 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set) => ({
   contextUsage: null,
   modelLoading: false,
   setModelLoading: (loading) => set({ modelLoading: loading }),
-  setParams: (params) => set({ params }),
+  setParams: (params) =>
+    set(() => {
+      const persisted = saveInferenceParams(params);
+      if (!persisted && !hasShownInferencePersistenceWarning) {
+        hasShownInferencePersistenceWarning = true;
+        toast.warning("Chat settings could not be persisted", {
+          description:
+            "Your changes apply now, but may reset after refresh.",
+        });
+      }
+      return { params };
+    }),
   setModels: (models) => set({ models }),
   setLoras: (loras) => set({ loras }),
   setThreadRunning: (threadId, running) =>