Add canonicalizations for tracking-* utilities

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - _Experimental_: Add `@container-size` utility ([#18901](https://github.com/tailwindlabs/tailwindcss/pull/18901))
 
+### Fixed
+
+- Improve canonicalizations for `tracking-*` utilities ([#19827](https://github.com/tailwindlabs/tailwindcss/pull/19827))
+
 ## [4.2.2] - 2026-03-18
 
 ### Fixed

packages/tailwindcss/src/canonicalize-candidates.test.ts

@@ -1120,6 +1120,40 @@ describe.each([['default'], ['with-variant'], ['important'], ['prefix']])('%s',
       await expectCombinedCanonicalization(input, candidates.trim(), expected)
     })
   })
+
+  // https://github.com/tailwindlabs/tailwindcss-intellisense/issues/1558
+  test.each([
+    ['tracking-[-0.05em]', 'tracking-tighter'],
+    ['tracking-[-0.025em]', 'tracking-tight'],
+    ['tracking-[0em]', 'tracking-normal'],
+    ['tracking-[0.025em]', 'tracking-wide'],
+    ['tracking-[0.05em]', 'tracking-wider'],
+    ['tracking-[0.1em]', 'tracking-widest'],
+
+    // Negative values that don't make sense
+    // See: https://tailwindcss.com/docs/letter-spacing#using-negative-values
+    ['-tracking-tighter', 'tracking-wider'],
+    ['-tracking-tight', 'tracking-wide'],
+    ['-tracking-normal', 'tracking-normal'],
+    ['-tracking-wide', 'tracking-tight'],
+    ['-tracking-wider', 'tracking-tighter'],
+  ])(testName, { timeout }, async (candidate, expected) => {
+    await expectCanonicalization(
+      css`
+        @import 'tailwindcss';
+        @theme {
+          --tracking-tighter: -0.05em;
+          --tracking-tight: -0.025em;
+          --tracking-normal: 0em;
+          --tracking-wide: 0.025em;
+          --tracking-wider: 0.05em;
+          --tracking-widest: 0.1em;
+        }
+      `,
+      candidate,
+      expected,
+    )
+  })
 })
 
 describe('theme to var', () => {

packages/tailwindcss/src/canonicalize-candidates.ts

@@ -1128,11 +1128,29 @@ function arbitraryUtilities(candidate: Candidate, options: InternalCanonicalizeO
     // Find a corresponding utility for the same signature
     let replacements = utilities.get(targetSignature)
 
-    // Multiple utilities can map to the same signature. Not sure how to migrate
-    // this one so let's just skip it for now.
-    //
-    // TODO: Do we just migrate to the first one?
-    if (replacements.length > 1) return
+    // Multiple utilities can map to the same signature.
+    if (replacements.length > 1) {
+      // Prefer positive values over negative values
+      let maybeReplacement: string | undefined = undefined
+      for (let replacement of replacements) {
+        if (replacement[0] === '-') continue // Skip negative values
+
+        // If multiple non-negative replacements exists then we are unsure
+        // what to do, so let's bail.
+        if (maybeReplacement) return
+
+        // Consider this replacement
+        maybeReplacement = replacement
+      }
+
+      if (maybeReplacement) {
+        for (let replacementCandidate of parseCandidate(designSystem, maybeReplacement)) {
+          yield replacementCandidate
+        }
+      }
+
+      return
+    }
 
     // If we didn't find any replacement utilities, let's try to strip the
     // modifier and find a replacement then. If we do, we can try to re-add the
@@ -1353,11 +1371,29 @@ function bareValueUtilities(candidate: Candidate, options: InternalCanonicalizeO
     // Find a corresponding utility for the same signature
     let replacements = utilities.get(targetSignature)
 
-    // Multiple utilities can map to the same signature. Not sure how to migrate
-    // this one so let's just skip it for now.
-    //
-    // TODO: Do we just migrate to the first one?
-    if (replacements.length > 1) return
+    // Multiple utilities can map to the same signature.
+    if (replacements.length > 1) {
+      // Prefer positive values over negative values
+      let maybeReplacement: string | undefined = undefined
+      for (let replacement of replacements) {
+        if (replacement[0] === '-') continue // Skip negative values
+
+        // If multiple non-negative replacements exists then we are unsure
+        // what to do, so let's bail.
+        if (maybeReplacement) return
+
+        // Consider this replacement
+        maybeReplacement = replacement
+      }
+
+      if (maybeReplacement) {
+        for (let replacementCandidate of parseCandidate(designSystem, maybeReplacement)) {
+          yield replacementCandidate
+        }
+      }
+
+      return
+    }
 
     // If we didn't find any replacement utilities, let's try to strip the
     // modifier and find a replacement then. If we do, we can try to re-add the