diff --git a/README.md b/README.md
index 5509e7d1..59acda12 100644
--- a/README.md
+++ b/README.md
@@ -120,7 +120,8 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     # Default: true
     clean: ''
 
-    # Partially clone against a given filter. Overrides sparse-checkout if set.
+    # Partially clone against a given filter. If sparse-checkout is set and filter is
+    # not, the filter is `blob:none`. Set to `none` to fetch without a filter.
     # Default: null
     filter: ''
 
diff --git a/__test__/git-command-manager.test.ts b/__test__/git-command-manager.test.ts
index e669c0f3..f03b587e 100644
--- a/__test__/git-command-manager.test.ts
+++ b/__test__/git-command-manager.test.ts
@@ -401,6 +401,41 @@ describe('Test fetchDepth and fetchTags options', () => {
       expect.any(Object)
     )
   })
+
+  it('should not pass --filter when filter is not set', async () => {
+    // exec.exec is already mockExec
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    const refSpec = ['refspec1']
+    const options = {
+      fetchDepth: 1
+    }
+
+    await git.fetch(refSpec, options)
+
+    expect(mockExec).toHaveBeenCalledWith(
+      expect.any(String),
+      [
+        '-c',
+        'protocol.version=2',
+        'fetch',
+        '--no-tags',
+        '--prune',
+        '--no-recurse-submodules',
+        '--depth=1',
+        'origin',
+        'refspec1'
+      ],
+      expect.any(Object)
+    )
+  })
 })
 
 describe('repository initialization object format', () => {
diff --git a/__test__/input-helper.test.ts b/__test__/input-helper.test.ts
index afe30fb8..323c9ed9 100644
--- a/__test__/input-helper.test.ts
+++ b/__test__/input-helper.test.ts
@@ -215,6 +215,47 @@ describe('input-helper tests', () => {
     expect(settings.commit).toBe('1111111111222222222233333333334444444444')
   })
 
+  describe('filter', () => {
+    it('is not set without sparse checkout', async () => {
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
+      expect(settings.filter).toBe(undefined)
+    })
+
+    it('defaults to blob:none with sparse checkout', async () => {
+      inputs['sparse-checkout'] = 'src\ndocs'
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
+      expect(settings.sparseCheckout).toEqual(['src', 'docs'])
+      expect(settings.filter).toBe('blob:none')
+    })
+
+    it('uses the given filter with sparse checkout', async () => {
+      inputs['sparse-checkout'] = 'src'
+      inputs.filter = 'tree:0'
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
+      expect(settings.filter).toBe('tree:0')
+    })
+
+    it('uses the given filter without sparse checkout', async () => {
+      inputs.filter = 'blob:limit=1m'
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
+      expect(settings.filter).toBe('blob:limit=1m')
+    })
+
+    it('is not set when none with sparse checkout', async () => {
+      inputs['sparse-checkout'] = 'src'
+      inputs.filter = 'none'
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
+      expect(settings.sparseCheckout).toEqual(['src'])
+      expect(settings.filter).toBe(undefined)
+    })
+
+    it('is not set when none without sparse checkout', async () => {
+      inputs.filter = 'None'
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
+      expect(settings.filter).toBe(undefined)
+    })
+  })
+
   it('sets workflow organization ID', async () => {
     const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.workflowOrganizationId).toBe(123456)
diff --git a/action.yml b/action.yml
index 5b0524f7..78875c36 100644
--- a/action.yml
+++ b/action.yml
@@ -60,7 +60,8 @@ inputs:
   filter:
     description: >
       Partially clone against a given filter.
-      Overrides sparse-checkout if set.
+      If sparse-checkout is set and filter is not, the filter is `blob:none`.
+      Set to `none` to fetch without a filter.
     default: null
   sparse-checkout:
     description: >
diff --git a/dist/index.js b/dist/index.js
index 06ae5d22..8caa5751 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -41810,9 +41810,6 @@ async function getSource(settings) {
         if (settings.filter) {
             fetchOptions.filter = settings.filter;
         }
-        else if (settings.sparseCheckout) {
-            fetchOptions.filter = 'blob:none';
-        }
         if (settings.fetchDepth <= 0) {
             // Fetch all branches and tags
             let refSpec = getRefSpecForAllHistory(settings.ref, settings.commit);
@@ -42137,18 +42134,26 @@ async function getInputs() {
     // Clean
     result.clean = (getInput('clean') || 'true').toUpperCase() === 'TRUE';
     core_debug(`clean = ${result.clean}`);
-    // Filter
-    const filter = getInput('filter');
-    if (filter) {
-        result.filter = filter;
-    }
-    core_debug(`filter = ${result.filter}`);
     // Sparse checkout
     const sparseCheckout = getMultilineInput('sparse-checkout');
     if (sparseCheckout.length) {
         result.sparseCheckout = sparseCheckout;
         core_debug(`sparse checkout = ${result.sparseCheckout}`);
     }
+    // Filter
+    // Sparse checkout implies 'blob:none' unless a filter is given.
+    // 'none' disables the filter.
+    const filter = getInput('filter');
+    if (filter.toUpperCase() === 'NONE') {
+        result.filter = undefined;
+    }
+    else if (filter) {
+        result.filter = filter;
+    }
+    else if (result.sparseCheckout) {
+        result.filter = 'blob:none';
+    }
+    core_debug(`filter = ${result.filter}`);
     result.sparseCheckoutConeMode =
         (getInput('sparse-checkout-cone-mode') || 'true').toUpperCase() ===
             'TRUE';
diff --git a/src/git-source-provider.ts b/src/git-source-provider.ts
index b9c1d357..dad5d358 100644
--- a/src/git-source-provider.ts
+++ b/src/git-source-provider.ts
@@ -181,8 +181,6 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
 
     if (settings.filter) {
       fetchOptions.filter = settings.filter
-    } else if (settings.sparseCheckout) {
-      fetchOptions.filter = 'blob:none'
     }
 
     if (settings.fetchDepth <= 0) {
diff --git a/src/git-source-settings.ts b/src/git-source-settings.ts
index 79041c43..eab36688 100644
--- a/src/git-source-settings.ts
+++ b/src/git-source-settings.ts
@@ -30,7 +30,8 @@ export interface IGitSourceSettings {
   clean: boolean
 
   /**
-   * The filter determining which objects to include
+   * The filter determining which objects to include.
+   * Defaults to 'blob:none' when sparse checkout is set, unless the input is 'none'.
    */
   filter: string | undefined
 
diff --git a/src/input-helper.ts b/src/input-helper.ts
index 9a98b867..b57150de 100644
--- a/src/input-helper.ts
+++ b/src/input-helper.ts
@@ -100,14 +100,6 @@ export async function getInputs(): Promise<IGitSourceSettings> {
   result.clean = (core.getInput('clean') || 'true').toUpperCase() === 'TRUE'
   core.debug(`clean = ${result.clean}`)
 
-  // Filter
-  const filter = core.getInput('filter')
-  if (filter) {
-    result.filter = filter
-  }
-
-  core.debug(`filter = ${result.filter}`)
-
   // Sparse checkout
   const sparseCheckout = core.getMultilineInput('sparse-checkout')
   if (sparseCheckout.length) {
@@ -115,6 +107,20 @@ export async function getInputs(): Promise<IGitSourceSettings> {
     core.debug(`sparse checkout = ${result.sparseCheckout}`)
   }
 
+  // Filter
+  // Sparse checkout implies 'blob:none' unless a filter is given.
+  // 'none' disables the filter.
+  const filter = core.getInput('filter')
+  if (filter.toUpperCase() === 'NONE') {
+    result.filter = undefined
+  } else if (filter) {
+    result.filter = filter
+  } else if (result.sparseCheckout) {
+    result.filter = 'blob:none'
+  }
+
+  core.debug(`filter = ${result.filter}`)
+
   result.sparseCheckoutConeMode =
     (core.getInput('sparse-checkout-cone-mode') || 'true').toUpperCase() ===
     'TRUE'