diff --git a/apps/desktop/src/app/shell/model-catalog-menu.search-fold.test.tsx b/apps/desktop/src/app/shell/model-catalog-menu.search-fold.test.tsx
new file mode 100644
index 0000000000..5473a1fdee
--- /dev/null
+++ b/apps/desktop/src/app/shell/model-catalog-menu.search-fold.test.tsx
@@ -0,0 +1,108 @@
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { DropdownMenu, DropdownMenuContent } from '@/components/ui/dropdown-menu'
+import { $localModelsEnabled } from '@/store/local-models-flag'
+import { $localRuntimeJobs } from '@/store/local-runtime-jobs'
+import { $visibleModels } from '@/store/model-visibility'
+
+import { ModelCatalogMenu, type ModelMenuController } from './model-catalog-menu'
+
+// Radix calls these on open; jsdom doesn't implement them.
+beforeAll(() => {
+  Element.prototype.scrollIntoView = vi.fn()
+  Element.prototype.hasPointerCapture = vi.fn(() => false)
+  Element.prototype.releasePointerCapture = vi.fn()
+})
+
+const getGlobalModelOptions = vi.fn()
+
+vi.mock('@/hermes', () => ({
+  getGlobalModelOptions: (...args: unknown[]) => getGlobalModelOptions(...args),
+  getLocalModelsJobs: vi.fn(async () => ({ jobs: [] })),
+  getLocalModelsStatus: vi.fn().mockResolvedValue({ loading: {} }),
+  setApiRequestProfile: vi.fn()
+}))
+
+beforeEach(() => {
+  $visibleModels.set(null)
+  $localRuntimeJobs.set([])
+  $localModelsEnabled.set(false)
+  getGlobalModelOptions.mockResolvedValue({
+    providers: [{ models: ['qwen3.8-flash', 'gpt-5.1'], name: 'OpenRouter', slug: 'openrouter' }]
+  })
+})
+
+afterEach(() => {
+  cleanup()
+  vi.clearAllMocks()
+})
+
+function renderMenu() {
+  const controller: ModelMenuController = {
+    applyPreset: vi.fn(),
+    current: { effort: '', fast: false, model: '', provider: '' },
+    presetFor: () => ({}),
+    select: vi.fn(async () => true),
+    setOptions: vi.fn()
+  }
+
+  const client = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+
+  render(
+    <QueryClientProvider client={client}>
+      <DropdownMenu open>
+        <DropdownMenuContent>
+          <ModelCatalogMenu controller={controller} />
+        </DropdownMenuContent>
+      </DropdownMenu>
+    </QueryClientProvider>
+  )
+}
+
+
+
+
+// The row label span (class "truncate") carries the full label text plus the
+// meta suffix ("High"/"Min"), so match by prefix. Works for both the plain
+// and the <mark>-split rendering.
+function rowTruncateSpan(prefix: string) {
+  return screen.queryByText((_, element) =>
+    Boolean(element?.classList.contains('truncate') && (element?.textContent ?? '').startsWith(prefix))
+  )
+}
+
+// The search filter and the highlight must agree: whatever a query reveals,
+// the row's label marks the query (separator-folded equivalence). Pre-fix,
+// hyphen queries revealed rows with zero marks, and space queries matched
+// only via the display segment - both polarity failures covered here.
+describe('model catalog search: fold between filter and highlight', () => {
+  it('HYPHEN query both filters and highlights the SPACED label (the reported defect - fails pre-fix)', async () => {
+    renderMenu()
+    await screen.findByText(/Qwen3\.8 Flash/i)
+
+    fireEvent.change(screen.getByRole('textbox', { name: 'Search models' }), { target: { value: 'qwen3.8-flash' } })
+
+    await vi.waitFor(() => {
+      // Whole label matches contiguously -> renders as a single <mark>.
+      expect(screen.getByText('Qwen3.8 Flash', { selector: 'mark' })).toBeDefined()
+    })
+  })
+
+  it('SPACE query finds the HYPHENATED id (superset guarantee) and highlights', async () => {
+    renderMenu()
+    await screen.findByText(/Qwen3\.8 Flash/i)
+
+    fireEvent.change(screen.getByRole('textbox', { name: 'Search models' }), { target: { value: 'qwen3 8' } })
+
+    await vi.waitFor(() => {
+      // Partial label match -> <mark>Qwen3.8</mark> + ' Flash'.
+      expect(screen.getByText('Qwen3.8', { selector: 'mark' })).toBeDefined()
+      // The row label (before the meta suffix) is intact.
+      expect(rowTruncateSpan('Qwen3.8 Flash')).toBeDefined()
+      // The fold must not over-match: a qwen query still hides GPT rows.
+      expect(rowTruncateSpan('GPT-5.1')).toBeNull()
+    })
+  })
+})
diff --git a/apps/desktop/src/app/shell/model-catalog-menu.test.tsx b/apps/desktop/src/app/shell/model-catalog-menu.test.tsx
index ae42a4a36c..6e8e1494bf 100644
--- a/apps/desktop/src/app/shell/model-catalog-menu.test.tsx
+++ b/apps/desktop/src/app/shell/model-catalog-menu.test.tsx
@@ -108,7 +108,16 @@ describe('the catalog owns model curation', () => {
     fireEvent.change(input, { target: { value: 'gemini-3.1' } })
 
     await vi.waitFor(() => {
-      expect(screen.queryByText(/Gemini 3\.1 Pro/i)).not.toBeNull()
+      // The fold makes this id-style query highlight the spaced label: the
+      // row renders as <mark>Gemini 3.1</mark> + ' Pro'.
+      expect(screen.getByText('Gemini 3.1', { selector: 'mark' })).toBeDefined()
+      // Display name is "Gemini 3.1 pro" (no title-case for gemini ids); the
+      // row label span carries it (plus the effort meta suffix).
+      expect(
+        screen.getByText((_, element) =>
+          Boolean(element?.classList.contains('truncate') && (element?.textContent ?? '').startsWith('Gemini 3.1 pro'))
+        )
+      ).toBeDefined()
     })
   })
 
diff --git a/apps/desktop/src/app/shell/model-catalog-menu.tsx b/apps/desktop/src/app/shell/model-catalog-menu.tsx
index 3cde3cd229..78c563ddea 100644
--- a/apps/desktop/src/app/shell/model-catalog-menu.tsx
+++ b/apps/desktop/src/app/shell/model-catalog-menu.tsx
@@ -24,7 +24,7 @@ import { useI18n } from '@/i18n'
 import { modelOptionsQueryKey, requestModelOptions } from '@/lib/model-options'
 import { displayModelName, modelDisplayParts } from '@/lib/model-status-label'
 import { DEFAULT_REASONING_EFFORT, reasoningEffortLabel } from '@/lib/reasoning-effort'
-import { normalize } from '@/lib/text'
+import { foldIncludes, normalize } from '@/lib/text'
 import { useStoreSelector } from '@/lib/use-session-slice'
 import { cn } from '@/lib/utils'
 import { $localModelsEnabled } from '@/store/local-models-flag'
@@ -265,7 +265,7 @@ export function ModelCatalogMenu({
   // In-flight downloads render inside the Local provider group when it
   // exists, else as their own trailing 'Local' group (first download —
   // nothing staged yet, so the catalog has no local provider row).
-  const shownDownloads = q ? downloads.filter(job => (job.target || '').toLowerCase().includes(q)) : downloads
+  const shownDownloads = q ? downloads.filter(job => foldIncludes(job.target || '', q)) : downloads
   const hasLocalGroup = pickerProviders.some(provider => provider.slug === LOCAL_PROVIDER_SLUG)
 
   // Resolve visibility HERE, against the catalog we actually fetched: an empty
@@ -285,7 +285,7 @@ export function ModelCatalogMenu({
   // sitting under zero model matches would otherwise become the "first match"
   // Enter commits.
   const shownMoaPresets = useMemo(
-    () => (q ? moaPresets.filter(preset => `moa ${preset}`.toLowerCase().includes(q)) : moaPresets),
+    () => (q ? moaPresets.filter(preset => foldIncludes(`moa ${preset}`, q)) : moaPresets),
     [moaPresets, q]
   )
 
@@ -729,9 +729,10 @@ function groupModels(
     }
 
     const matches = (family: ModelFamily) =>
-      `${family.id} ${family.fastId ?? ''} ${provider.name} ${provider.slug} ${displayModelName(family.id)}`
-        .toLowerCase()
-        .includes(q)
+      foldIncludes(
+        `${family.id} ${family.fastId ?? ''} ${provider.name} ${provider.slug} ${displayModelName(family.id)}`,
+        q
+      )
 
     let shown: Set<string>
 
diff --git a/apps/desktop/src/components/model-picker.tsx b/apps/desktop/src/components/model-picker.tsx
index f2d7283f17..e36bc27def 100644
--- a/apps/desktop/src/components/model-picker.tsx
+++ b/apps/desktop/src/components/model-picker.tsx
@@ -6,7 +6,7 @@ import { useI18n } from '@/i18n'
 import { modelOptionsQueryKey, requestModelOptions } from '@/lib/model-options'
 import { modelSearchText } from '@/lib/model-search-text'
 import { currentPickerSelection } from '@/lib/model-status-label'
-import { normalize } from '@/lib/text'
+import { foldIncludes, normalize } from '@/lib/text'
 import { useStoreSelector } from '@/lib/use-session-slice'
 import { $localModelsEnabled } from '@/store/local-models-flag'
 import { $localRuntimeJobs, runningModelDownloads, watchLocalRuntimeJobs } from '@/store/local-runtime-jobs'
@@ -266,9 +266,9 @@ function ModelResults({
 
   const matches = (provider: ModelOptionProvider, model: string) =>
     !q ||
-    modelSearchText(model).toLowerCase().includes(q) ||
-    provider.name.toLowerCase().includes(q) ||
-    provider.slug.toLowerCase().includes(q)
+    foldIncludes(modelSearchText(model), q) ||
+    foldIncludes(provider.name, q) ||
+    foldIncludes(provider.slug, q)
 
   // Only configured providers (those with curated models) are selectable
   // here. Switching to a NOT-yet-configured provider goes through the
diff --git a/apps/desktop/src/components/model-visibility-dialog.tsx b/apps/desktop/src/components/model-visibility-dialog.tsx
index 5fe32d929a..626d5c59c9 100644
--- a/apps/desktop/src/components/model-visibility-dialog.tsx
+++ b/apps/desktop/src/components/model-visibility-dialog.tsx
@@ -14,7 +14,7 @@ import { useI18n } from '@/i18n'
 import { Search } from '@/lib/icons'
 import { modelOptionsQueryKey, requestModelOptions } from '@/lib/model-options'
 import { displayModelName, modelDisplayParts } from '@/lib/model-status-label'
-import { normalize } from '@/lib/text'
+import { foldIncludes, normalize } from '@/lib/text'
 import {
   $visibleModels,
   collapseModelFamilies,
@@ -76,7 +76,7 @@ export function ModelVisibilityDialog({
   const q = normalize(search)
 
   const matches = (provider: ModelOptionProvider, model: string) =>
-    !q || `${model} ${provider.name} ${provider.slug} ${displayModelName(model)}`.toLowerCase().includes(q)
+    !q || foldIncludes(`${model} ${provider.name} ${provider.slug} ${displayModelName(model)}`, q)
 
   return (
     <Dialog onOpenChange={onOpenChange} open={open}>
diff --git a/apps/desktop/src/components/ui/dropdown-menu.tsx b/apps/desktop/src/components/ui/dropdown-menu.tsx
index 83ddb9fb12..465e2efab4 100644
--- a/apps/desktop/src/components/ui/dropdown-menu.tsx
+++ b/apps/desktop/src/components/ui/dropdown-menu.tsx
@@ -61,6 +61,10 @@ function DropdownMenuSearch({
 
           onKeyDown?.(event)
         }}
+        // Search fields here filter ids, slugs, and model names — dictionary
+        // squiggles under them are noise (matching the composer/settings
+        // inputs, which already disable spellcheck).
+        spellCheck={false}
         type="text"
         {...props}
       />
diff --git a/apps/desktop/src/components/ui/highlight-matches.test.tsx b/apps/desktop/src/components/ui/highlight-matches.test.tsx
index 2c9f158c75..d993998860 100644
--- a/apps/desktop/src/components/ui/highlight-matches.test.tsx
+++ b/apps/desktop/src/components/ui/highlight-matches.test.tsx
@@ -5,41 +5,43 @@ import { HighlightMatches } from './highlight-matches'
 
 const marksOf = (container: HTMLElement) => Array.from(container.querySelectorAll('mark')).map(m => m.textContent)
 
-describe('HighlightMatches', () => {
-  it('wraps every case-insensitive occurrence in a <mark> without altering the text', () => {
-    const { container } = render(<HighlightMatches query="ro" text="Grok 4.5 Retro" />)
+describe('HighlightMatches with separator folding', () => {
+  it('HYPHEN query marks the SPACED label (the reported defect — fails pre-fix)', () => {
+    const { container } = render(<HighlightMatches query="qwen3.8-flash" text="Qwen3.8 Flash" />)
 
-    expect(container.textContent).toBe('Grok 4.5 Retro')
-    expect(marksOf(container)).toEqual(['ro', 'ro'])
+    expect(marksOf(container)).toEqual(['Qwen3.8 Flash'])
   })
 
-  it('renders plain text when the query is empty or does not occur in this label', () => {
-    // Non-occurrence matters: rows can match the filter on id/slug while the
-    // display label contains no occurrence — must not crash or mis-mark.
-    for (const query of ['', '   ', 'zzz']) {
-      const { container } = render(<HighlightMatches query={query} text="Fable 5" />)
+  it('SPACE query marks the HYPHENATED text (model-picker polarity)', () => {
+    const { container } = render(<HighlightMatches query="qwen3 8 flash" text="qwen3.8-flash" />)
 
-      expect(container.textContent).toBe('Fable 5')
-      expect(container.querySelector('mark')).toBeNull()
-    }
+    expect(marksOf(container)).toEqual(['qwen3.8-flash'])
   })
 
-  it('normalizes the query the same way the pickers filter (trim + lowercase)', () => {
-    const { container } = render(<HighlightMatches query="  GROK " text="grok-4.5" />)
+  it('folding must not shift mark indices: slices return the ORIGINAL characters', () => {
+    const { container } = render(<HighlightMatches query="gpt 5" text="GPT-5 Turbo" />)
 
-    expect(marksOf(container)).toEqual(['grok'])
+    // mark covers "GPT-5" exactly — original characters, not folded ones.
+    expect(marksOf(container)).toEqual(['GPT-5'])
+    expect(container.textContent).toBe('GPT-5 Turbo')
   })
 
-  it('marks every term of a multi-term query (palette AND semantics)', () => {
-    const { container } = render(<HighlightMatches query={['open', 'set']} text="Open Settings" />)
+  it('literal spaces in the label are marked as part of the range', () => {
+    const { container } = render(<HighlightMatches query="3 8 f" text="Qwen3.8 Flash" />)
 
-    expect(container.textContent).toBe('Open Settings')
-    expect(marksOf(container)).toEqual(['Open', 'Set'])
+    expect(marksOf(container)).toEqual(['3.8 F'])
   })
 
-  it('merges overlapping and adjacent term ranges into one mark', () => {
-    const { container } = render(<HighlightMatches query={['gro', 'rok']} text="Grok" />)
+  it('prefix queries still mark (existing contract intact)', () => {
+    const { container } = render(<HighlightMatches query="qwen3.8" text="Qwen3.8 Flash" />)
 
-    expect(marksOf(container)).toEqual(['Grok'])
+    expect(marksOf(container)).toEqual(['Qwen3.8'])
+  })
+
+  it('non-matching queries render plain text', () => {
+    const { container } = render(<HighlightMatches query="zzz-9" text="Qwen3.8 Flash" />)
+
+    expect(container.querySelector('mark')).toBeNull()
+    expect(container.textContent).toBe('Qwen3.8 Flash')
   })
 })
diff --git a/apps/desktop/src/components/ui/highlight-matches.tsx b/apps/desktop/src/components/ui/highlight-matches.tsx
index 2d05ebc066..1e685d2d67 100644
--- a/apps/desktop/src/components/ui/highlight-matches.tsx
+++ b/apps/desktop/src/components/ui/highlight-matches.tsx
@@ -1,6 +1,6 @@
 import type { ReactNode } from 'react'
 
-import { normalize } from '@/lib/text'
+import { normalize, searchFold } from '@/lib/text'
 import { cn } from '@/lib/utils'
 
 /**
@@ -13,9 +13,14 @@ import { cn } from '@/lib/utils'
  * The query must mirror the surface's OWN filter semantics, or the emphasis
  * lies about why a row matched:
  * - a string for literal-substring filters (the model pickers) — spaces and
- *   all, exactly what `.includes()` saw;
+ *   all, exactly what the filter saw, after the shared `searchFold` runs on
+ *   BOTH sides (separators -_. and case stop mattering, mirroring
+ *   `foldIncludes` — a hyphen query must light up the spaced label);
  * - a string[] for per-term AND matchers (the command palette) — every term
  *   is marked wherever it occurs, overlapping/adjacent ranges merged.
+ *
+ * The fold is length-preserving, so ranges found in the folded text index
+ * the original unchanged — marks slice the original characters.
  */
 export function HighlightMatches({
   className,
@@ -32,7 +37,7 @@ export function HighlightMatches({
     return <>{text}</>
   }
 
-  const ranges = matchRanges(text.toLowerCase(), terms)
+  const ranges = matchRanges(searchFold(text), terms.map(searchFold))
 
   if (ranges.length === 0) {
     // No occurrence (the row matched on its id/slug/keywords, not this label).
diff --git a/apps/desktop/src/lib/text.test.ts b/apps/desktop/src/lib/text.test.ts
new file mode 100644
index 0000000000..c34b4a3ae0
--- /dev/null
+++ b/apps/desktop/src/lib/text.test.ts
@@ -0,0 +1,45 @@
+import { describe, expect, it } from 'vitest'
+
+import { foldIncludes, searchFold } from './text'
+
+describe('searchFold', () => {
+  it('folds separator characters to spaces, both directions equivalent', () => {
+    expect(searchFold('qwen3.8-flash')).toBe('qwen3 8 flash')
+    expect(searchFold('Qwen3.8 Flash')).toBe('qwen3 8 flash')
+    expect(searchFold('GPT-5')).toBe('gpt 5')
+    expect(searchFold('gpt 5')).toBe('gpt 5')
+    expect(searchFold('Q4_K_XL')).toBe('q4 k xl')
+  })
+
+  it('is length-preserving (1 char in, 1 char out) so highlight indices survive', () => {
+    for (const text of ['qwen3.8-flash', 'GPT-5', 'a--b__c..d', 'Grok 4.5 Retro', '']) {
+      expect(searchFold(text).length).toBe(text.length)
+    }
+  })
+
+  it('already-folded text is unchanged (idempotent)', () => {
+    expect(searchFold('qwen3 8 flash')).toBe('qwen3 8 flash')
+  })
+})
+
+describe('foldIncludes', () => {
+  it('matches across the hyphen/space/dot/underscore separator difference', () => {
+    expect(foldIncludes('Qwen3.8 Flash', 'qwen3.8-flash')).toBe(true)
+    expect(foldIncludes('qwen3.8-flash', 'qwen3 8 flash')).toBe(true)
+    expect(foldIncludes('GPT-5', 'gpt 5')).toBe(true)
+    expect(foldIncludes('gpt-5', 'GPT.5')).toBe(true)
+    expect(foldIncludes('Q4_K_XL', 'q4 k xl')).toBe(true)
+  })
+
+  it('is a superset of the plain-lowercase includes it replaces', () => {
+    // Any query that matched before must still match.
+    expect(foldIncludes('qwen3.8-flash', 'qwen3.8')).toBe(true)
+    expect(foldIncludes('Qwen3.8 Flash', 'flash')).toBe(true)
+    expect(foldIncludes('nous-portal', 'nous')).toBe(true)
+  })
+
+  it('still rejects genuinely different text', () => {
+    expect(foldIncludes('Gemini Flash', 'qwen')).toBe(false)
+    expect(foldIncludes('gpt-5', 'gpt-6')).toBe(false)
+  })
+})
diff --git a/apps/desktop/src/lib/text.ts b/apps/desktop/src/lib/text.ts
index eecb0cc715..a4e8077587 100644
--- a/apps/desktop/src/lib/text.ts
+++ b/apps/desktop/src/lib/text.ts
@@ -27,3 +27,19 @@ export const firstStringField = (record: Record<string, unknown>, keys: readonly
 
   return ''
 }
+
+/** Search-equivalence fold: separators (`-`, `_`, `.`) and case stop matter —
+ *  `qwen3.8-flash`, `Qwen3.8 Flash` and `qwen3 8_flash` all fold to the same
+ *  string. One char in, one char out (length preserved), so highlight ranges
+ *  computed on folded text index the ORIGINAL text unchanged. Model ids use
+ *  hyphens, display names use spaces, quants use underscores — a picker search
+ *  must not care. Filter and highlight MUST call this on BOTH sides; a fold on
+ *  only one is what made hyphen queries match without ever highlighting. */
+export function searchFold(v: unknown): string {
+  return asText(v).toLowerCase().replace(/[-_.]/g, ' ')
+}
+
+/** `searchFold` + substring: the one matcher every searchable picker uses. */
+export function foldIncludes(text: unknown, query: unknown): boolean {
+  return searchFold(text).includes(searchFold(query))
+}