diff --git a/lib/languages.ts b/lib/languages.ts
index 0e9d5e4318c..93eb33dba2b 100644
--- a/lib/languages.ts
+++ b/lib/languages.ts
@@ -38,7 +38,8 @@ type DefKeys =
     | 'logoUrl'
     | 'logoUrlDark'
     | 'monacoDisassembly'
-    | 'tooltip';
+    | 'tooltip'
+    | 'digitSeparator';
 type LanguageDefinition = Pick<Language, DefKeys>;
 
 const definitions: Record<LanguageKey, LanguageDefinition> = {
@@ -63,6 +64,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: 'clangformat',
         previewFilter: /^\s*#include/,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     ada: {
         name: 'Ada',
@@ -97,6 +99,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     'android-kotlin': {
         name: 'Android Kotlin',
@@ -108,6 +111,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     assembly: {
         name: 'Assembly',
@@ -130,6 +134,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: 'clangformat',
         previewFilter: /^\s*#include/,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     c3: {
         name: 'C3',
@@ -163,6 +168,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         logoUrlDark: null,
         formatter: null,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     circt: {
         name: 'CIRCT',
@@ -229,6 +235,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     mlir: {
         name: 'MLIR',
@@ -251,6 +258,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: /^\s*#include/,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     cppx_blue: {
         name: 'Cppx-Blue',
@@ -273,6 +281,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     cpp2_cppfront: {
         name: 'Cpp2-cppfront',
@@ -284,6 +293,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: 'cppp',
+        digitSeparator: "'",
     },
     crystal: {
         name: 'Crystal',
@@ -295,6 +305,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     csharp: {
         name: 'C#',
@@ -306,6 +317,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     cuda: {
         name: 'CUDA C++',
@@ -317,6 +329,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     d: {
         name: 'D',
@@ -394,6 +407,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     haskell: {
         name: 'Haskell',
@@ -405,6 +419,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     hlsl: {
         name: 'HLSL',
@@ -460,6 +475,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     julia: {
         name: 'Julia',
@@ -471,6 +487,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     kotlin: {
         name: 'Kotlin',
@@ -482,6 +499,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     llvm: {
         name: 'LLVM IR',
@@ -548,6 +566,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: "'",
     },
     ocaml: {
         name: 'OCaml',
@@ -603,6 +622,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     racket: {
         name: 'Racket',
@@ -625,6 +645,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: 'asmruby',
+        digitSeparator: '_',
     },
     rust: {
         name: 'Rust',
@@ -636,6 +657,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: 'rustfmt',
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     snowball: {
         name: 'Snowball',
@@ -658,6 +680,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     solidity: {
         name: 'Solidity',
@@ -691,6 +714,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     tablegen: {
         name: 'LLVM TableGen',
@@ -724,6 +748,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     v: {
         name: 'V',
@@ -768,6 +793,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     javascript: {
         name: 'Javascript',
@@ -779,6 +805,7 @@ const definitions: Record<LanguageKey, LanguageDefinition> = {
         formatter: null,
         previewFilter: null,
         monacoDisassembly: null,
+        digitSeparator: '_',
     },
     gimple: {
         name: 'GIMPLE',
diff --git a/shared/common-utils.ts b/shared/common-utils.ts
index 9a2481c0918..f339b6082c5 100644
--- a/shared/common-utils.ts
+++ b/shared/common-utils.ts
@@ -76,3 +76,26 @@ const EscapeRE = new RegExp(`(?:${Object.keys(EscapeMap).join('|')})`, 'g');
 export function escapeHTML(text: string) {
     return text.replace(EscapeRE, str => EscapeMap[str]);
 }
+
+function splitIntoChunks(s: string, chunkSize: number): string[] {
+    const chunks: string[] = [];
+    const isNegative = s.slice(0, 1) === '-';
+    if (isNegative) {
+        s = s.slice(1);
+    }
+    const firstChunkLength = s.length % chunkSize;
+    if (firstChunkLength !== 0) {
+        chunks.push(s.slice(0, firstChunkLength));
+    }
+    for (let i = firstChunkLength; i < s.length; i += chunkSize) {
+        chunks.push(s.slice(i, i + chunkSize));
+    }
+    if (isNegative) {
+        chunks[0] = '-' + (chunks[0] ?? '');
+    }
+    return chunks;
+}
+
+export function addDigitSeparator(n: string, digitSeparator: string, chunkSize: number): string {
+    return splitIntoChunks(n, chunkSize).join(digitSeparator);
+}
diff --git a/static/panes/compiler.ts b/static/panes/compiler.ts
index ad7d2b37802..9513f46a3a6 100644
--- a/static/panes/compiler.ts
+++ b/static/panes/compiler.ts
@@ -80,7 +80,7 @@ import {CompilerShared} from '../compiler-shared.js';
 import {SentryCapture} from '../sentry.js';
 import {LLVMIrBackendOptions} from '../compilation/ir.interfaces.js';
 import {InstructionSet} from '../instructionsets.js';
-import {escapeHTML} from '../../shared/common-utils.js';
+import {addDigitSeparator, escapeHTML} from '../../shared/common-utils.js';
 import {CompilerVersionInfo, setCompilerVersionPopoverForPane} from '../widgets/compiler-version-info.js';
 
 const toolIcons = require.context('../../views/resources/logos', false, /\.(png|svg)$/);
@@ -3496,7 +3496,15 @@ export class Compiler extends MonacoPane<monaco.editor.IStandaloneCodeEditor, Co
         return null;
     }
 
-    public static getNumericToolTip(value: string) {
+    public static getNumericToolTip(value: string, digitSeparator?: string) {
+        const formatNumber = (number, base, chunkSize) => {
+            const numberString = number.toString(base).toUpperCase();
+            if (digitSeparator !== undefined) {
+                return addDigitSeparator(numberString, digitSeparator, chunkSize);
+            } else {
+                return numberString;
+            }
+        };
         const numericValue = this.parseNumericValue(value);
         if (numericValue === null) return null;
 
@@ -3507,14 +3515,14 @@ export class Compiler extends MonacoPane<monaco.editor.IStandaloneCodeEditor, Co
         if (this.ptxFloat64.test(value)) return view.getFloat64(0, true).toPrecision(17);
 
         // Decimal representation.
-        let result = numericValue.toString(10);
+        let result = formatNumber(numericValue, 10, 3);
 
         // Hexadecimal representation.
         if (numericValue.isNegative()) {
             const masked = bigInt('ffffffffffffffff', 16).and(numericValue);
-            result += ' = 0x' + masked.toString(16).toUpperCase();
+            result += ' = 0x' + formatNumber(masked, 16, 4);
         } else {
-            result += ' = 0x' + numericValue.toString(16).toUpperCase();
+            result += ' = 0x' + formatNumber(numericValue, 16, 4);
         }
 
         // Float32/64 representation.
@@ -3627,7 +3635,9 @@ export class Compiler extends MonacoPane<monaco.editor.IStandaloneCodeEditor, Co
                 e.target.position.lineNumber,
                 currentWord.endColumn,
             );
-            const numericToolTip = Compiler.getNumericToolTip(word);
+            const lang = this.compiler?.lang;
+            const language = lang === undefined ? undefined : languages[lang];
+            const numericToolTip = Compiler.getNumericToolTip(word, language?.digitSeparator);
             if (numericToolTip) {
                 this.decorations.numericToolTip = [
                     {
diff --git a/test/common-utils-tests.ts b/test/common-utils-tests.ts
index 0ade79f2712..bc3bb4b3e6b 100644
--- a/test/common-utils-tests.ts
+++ b/test/common-utils-tests.ts
@@ -22,7 +22,7 @@
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.
 
-import {escapeHTML} from '../shared/common-utils.js';
+import {addDigitSeparator, escapeHTML} from '../shared/common-utils.js';
 
 describe('HTML Escape Test Cases', () => {
     it('should prevent basic injection', () => {
@@ -32,3 +32,24 @@ describe('HTML Escape Test Cases', () => {
         escapeHTML('\'"`>').should.equal(`&#x27;&quot;&#x60;&gt;`);
     });
 });
+
+describe('digit separator', () => {
+    it('handles short numbers', () => {
+        addDigitSeparator('42', '_', 3).should.equal('42');
+    });
+    it('handles long numbers', () => {
+        addDigitSeparator('1234', '_', 3).should.equal('1_234');
+        addDigitSeparator('123456789', "'", 3).should.equal("123'456'789");
+        addDigitSeparator('1234567890', "'", 3).should.equal("1'234'567'890");
+    });
+    it('handles hex numbers', () => {
+        addDigitSeparator('AABBCCDD12345678', '_', 4).should.equal('AABB_CCDD_1234_5678');
+        addDigitSeparator('01AABBCCDD12345678', '_', 4).should.equal('01_AABB_CCDD_1234_5678');
+    });
+    it('handles negative numbers', () => {
+        addDigitSeparator('-42', '_', 3).should.equal('-42');
+        addDigitSeparator('-420', '_', 3).should.equal('-420');
+        addDigitSeparator('-4200', '_', 3).should.equal('-4_200');
+        addDigitSeparator('-123456789', '_', 3).should.equal('-123_456_789');
+    });
+});
diff --git a/types/languages.interfaces.ts b/types/languages.interfaces.ts
index 8bdd26b56d9..a50a81b368f 100644
--- a/types/languages.interfaces.ts
+++ b/types/languages.interfaces.ts
@@ -124,4 +124,5 @@ export interface Language {
     tooltip?: string;
     /** Default compiler for the language. This is populated when handed to the frontend. */
     defaultCompiler?: string;
+    digitSeparator?: string;
 }