diff --git a/src/console/progressBar.ts b/src/console/progressBar.ts
index 1227ff916..4c0c374e6 100644
--- a/src/console/progressBar.ts
+++ b/src/console/progressBar.ts
@@ -23,6 +23,7 @@ export const ProgressBarSymbol = {
   // Candidates
   GENERATING: chalk.cyan('Σ'),
   FILTERING: chalk.cyan('∆'),
+  EXTENSION_CORRECTION: chalk.cyan('.'),
   HASHING: chalk.cyan('#'),
   VALIDATING: chalk.cyan(process.platform === 'win32' ? '?' : '≟'),
   COMBINING_ALL: chalk.cyan(process.platform === 'win32' ? 'U' : '∪'),
diff --git a/src/modules/candidateExtensionCorrector.ts b/src/modules/candidateExtensionCorrector.ts
index 570bc5df0..e31193dd5 100644
--- a/src/modules/candidateExtensionCorrector.ts
+++ b/src/modules/candidateExtensionCorrector.ts
@@ -7,7 +7,7 @@ import DAT from '../types/dats/dat.js';
 import Parent from '../types/dats/parent.js';
 import ROM from '../types/dats/rom.js';
 import ArchiveEntry from '../types/files/archives/archiveEntry.js';
-import FileSignature from '../types/files/fileSignature.js';
+import FileCache from '../types/files/fileCache.js';
 import Options, { FixExtension } from '../types/options.js';
 import OutputFactory from '../types/outputFactory.js';
 import ReleaseCandidate from '../types/releaseCandidate.js';
@@ -52,7 +52,7 @@ export default class CandidateExtensionCorrector extends Module {
       .filter((romWithFiles) => this.romNeedsCorrecting(romWithFiles))
       .length;
     this.progressBar.logTrace(`${dat.getNameShort()}: correcting ${romsThatNeedCorrecting.toLocaleString()} output file extension${romsThatNeedCorrecting !== 1 ? 's' : ''}`);
-    await this.progressBar.setSymbol(ProgressBarSymbol.HASHING);
+    await this.progressBar.setSymbol(ProgressBarSymbol.EXTENSION_CORRECTION);
     await this.progressBar.reset(romsThatNeedCorrecting);
 
     const correctedParentsToCandidates = await this.correctExtensions(dat, parentsToCandidates);
@@ -148,13 +148,8 @@ export default class CandidateExtensionCorrector extends Module {
       this.progressBar.logTrace(`${dat.getNameShort()}: ${parent.getName()}: correcting extension for: ${romWithFiles.getInputFile()
         .toString()}`);
 
-      await romWithFiles.getInputFile().createReadStream(async (stream) => {
-        const romSignature = await FileSignature.signatureFromFileStream(stream);
-        if (!romSignature) {
-          // No signature was found, so we can't perform any correction
-          return;
-        }
-
+      const romSignature = await FileCache.getOrComputeFileSignature(romWithFiles.getInputFile());
+      if (romSignature) {
         // ROM file signature found, use the appropriate extension
         const { dir, name } = path.parse(correctedRom.getName());
         const correctedRomName = path.format({
@@ -162,7 +157,7 @@ export default class CandidateExtensionCorrector extends Module {
           name: name + romSignature.getExtension(),
         });
         correctedRom = correctedRom.withName(correctedRomName);
-      });
+      }
 
       this.progressBar.removeWaitingMessage(waitingMessage);
       await this.progressBar.incrementDone();
diff --git a/src/types/cache.ts b/src/types/cache.ts
index 38270dec5..dccc88f4e 100644
--- a/src/types/cache.ts
+++ b/src/types/cache.ts
@@ -135,16 +135,17 @@ export default class Cache<V> {
    * Delete a key in the cache.
    */
   public async delete(key: string | RegExp): Promise<void> {
-    let keys: string[];
+    let keysToDelete: string[];
     if (key instanceof RegExp) {
-      keys = [...this.keys().keys()].filter((k) => k.match(key));
+      keysToDelete = [...this.keys().keys()].filter((k) => k.match(key));
     } else {
-      keys = [key];
+      keysToDelete = [key];
     }
 
-    await Promise.all(keys.map(async (k) => {
-      await this.lockKey(k, () => this.deleteUnsafe(k));
-    }));
+    // Note: avoiding lockKey() because it could get expensive with many keys to delete
+    await this.keyMutexesMutex.runExclusive(() => {
+      keysToDelete.forEach((k) => this.deleteUnsafe(k));
+    });
   }
 
   private deleteUnsafe(key: string): void {
diff --git a/src/types/files/fileCache.ts b/src/types/files/fileCache.ts
index 1ff231586..b0021d764 100644
--- a/src/types/files/fileCache.ts
+++ b/src/types/files/fileCache.ts
@@ -6,6 +6,7 @@ import Archive from './archives/archive.js';
 import ArchiveEntry, { ArchiveEntryProps } from './archives/archiveEntry.js';
 import File, { FileProps } from './file.js';
 import { ChecksumBitmask } from './fileChecksums.js';
+import FileSignature from './fileSignature.js';
 import ROMHeader from './romHeader.js';
 
 interface CacheValue {
@@ -14,11 +15,15 @@ interface CacheValue {
   value: FileProps | ArchiveEntryProps<Archive>[] | string | undefined,
 }
 
-enum ValueType {
-  FILE_CHECKSUMS = 'F',
-  ARCHIVE_CHECKSUMS = 'A',
-  FILE_HEADER = 'H',
-}
+const ValueType = {
+  FILE_CHECKSUMS: 'F',
+  ARCHIVE_CHECKSUMS: 'A',
+  // ROM headers and file signatures may not be found for files, and that is a valid result that
+  // gets cached. But when the list of known headers or signatures changes, we may be able to find
+  // a non-undefined result. So these dynamic values help with cache busting.
+  ROM_HEADER: `H${ROMHeader.getKnownHeaderCount()}`,
+  FILE_SIGNATURE: `S${FileSignature.getKnownSignatureCount()}`,
+};
 
 export default class FileCache {
   private static readonly VERSION = 3;
@@ -45,7 +50,8 @@ export default class FileCache {
         const keyRegex = new RegExp(`^V${prevVersion}\\|`);
         return this.cache.delete(keyRegex);
       }));
-    // await this.cache.delete(new RegExp(`\\|[^${Object.values(ValueType).join()}]$`));
+    // Delete keys from old value types
+    await this.cache.delete(new RegExp(`\\|(?!(${Object.values(ValueType).join('|')}))[^|]+$`));
 
     // Delete keys for deleted files
     const disks = FsPoly.disksSync();
@@ -198,7 +204,7 @@ export default class FileCache {
   static async getOrComputeFileHeader(file: File): Promise<ROMHeader | undefined> {
     // NOTE(cemmer): we're explicitly not catching ENOENT errors here, we want it to bubble up
     const stats = await FsPoly.stat(file.getFilePath());
-    const cacheKey = this.getCacheKey(file.toString(), ValueType.FILE_HEADER);
+    const cacheKey = this.getCacheKey(file.toString(), ValueType.ROM_HEADER);
 
     const cachedValue = await this.cache.getOrCompute(
       cacheKey,
@@ -214,10 +220,11 @@ export default class FileCache {
       },
       (cached) => {
         if (cached.fileSize !== stats.size || cached.modifiedTimeMillis !== stats.mtimeMs) {
-          // File has changed since being cached
+          // Recompute if the file has changed since being cached
           return true;
         }
-        return false;
+        // Recompute if the cached value isn't known
+        return typeof cached.value === 'string' && !ROMHeader.headerFromName(cached.value);
       },
     );
 
@@ -228,7 +235,41 @@ export default class FileCache {
     return ROMHeader.headerFromName(cachedHeaderName);
   }
 
-  private static getCacheKey(filePath: string, valueType: ValueType): string {
+  static async getOrComputeFileSignature(file: File): Promise<FileSignature | undefined> {
+    // NOTE(cemmer): we're explicitly not catching ENOENT errors here, we want it to bubble up
+    const stats = await FsPoly.stat(file.getFilePath());
+    const cacheKey = this.getCacheKey(file.toString(), ValueType.FILE_SIGNATURE);
+
+    const cachedValue = await this.cache.getOrCompute(
+      cacheKey,
+      async () => {
+        const signature = await file.createReadStream(
+          async (stream) => FileSignature.signatureFromFileStream(stream),
+        );
+        return {
+          fileSize: stats.size,
+          modifiedTimeMillis: stats.mtimeMs,
+          value: signature?.getName(),
+        };
+      },
+      (cached) => {
+        if (cached.fileSize !== stats.size || cached.modifiedTimeMillis !== stats.mtimeMs) {
+          // File has changed since being cached
+          return true;
+        }
+        // Recompute if the cached value isn't known
+        return typeof cached.value === 'string' && !FileSignature.signatureFromName(cached.value);
+      },
+    );
+
+    const cachedSignatureName = cachedValue.value as string | undefined;
+    if (!cachedSignatureName) {
+      return undefined;
+    }
+    return FileSignature.signatureFromName(cachedSignatureName);
+  }
+
+  private static getCacheKey(filePath: string, valueType: string): string {
     return `V${FileCache.VERSION}|${filePath}|${valueType}`;
   }
 }
diff --git a/src/types/files/fileFactory.ts b/src/types/files/fileFactory.ts
index f5cc86ae6..450dba971 100644
--- a/src/types/files/fileFactory.ts
+++ b/src/types/files/fileFactory.ts
@@ -110,9 +110,7 @@ export default class FileFactory {
     let signature: FileSignature | undefined;
     try {
       const file = await File.fileOf({ filePath });
-      signature = await file.createReadStream(
-        async (stream) => FileSignature.signatureFromFileStream(stream),
-      );
+      signature = await FileCache.getOrComputeFileSignature(file);
     } catch {
       // Fail silently on assumed I/O errors
       return undefined;
diff --git a/src/types/files/fileSignature.ts b/src/types/files/fileSignature.ts
index 5922e05c9..116a3aab3 100644
--- a/src/types/files/fileSignature.ts
+++ b/src/types/files/fileSignature.ts
@@ -1,5 +1,7 @@
 import { Readable } from 'node:stream';
 
+import { Memoize } from 'typescript-memoize';
+
 type SignaturePiece = {
   offset?: number,
   value: Buffer,
@@ -10,197 +12,200 @@ export default class FileSignature {
   // @see https://www.garykessler.net/library/file_sigs.html
   // @see https://file-extension.net/seeker/
   // @see https://gbatemp.net/threads/help-with-rom-iso-console-identification.611378/
-  private static readonly SIGNATURES = [
+  private static readonly SIGNATURES: { [key: string]: FileSignature } = {
     // ********** ARCHIVES **********
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.7z', [{ value: Buffer.from('377ABCAF271C', 'hex') }]),
+    '7z': new FileSignature('.7z', [{ value: Buffer.from('377ABCAF271C', 'hex') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.bz2', [{ value: Buffer.from('BZh') }]),
+    bz2: new FileSignature('.bz2', [{ value: Buffer.from('BZh') }]),
 
     // @see https://docs.fileformat.com/compression/gz/
-    new FileSignature('.gz', [{ value: Buffer.from('1F8B08', 'hex') }]), // deflate
+    gz: new FileSignature('.gz', [{ value: Buffer.from('1F8B08', 'hex') }]), // deflate
     // .tar.gz has the same file signature
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.lz', [{ value: Buffer.from('LZIP') }]),
+    lz: new FileSignature('.lz', [{ value: Buffer.from('LZIP') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.lz4', [{ value: Buffer.from('04224D18', 'hex') }]),
+    lz4: new FileSignature('.lz4', [{ value: Buffer.from('04224D18', 'hex') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.lzh', [
+    lzh: new FileSignature('.lzh', [
       { value: Buffer.from('-lh') },
       { offset: 4, value: Buffer.from('-') },
     ]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.oar', [{ value: Buffer.from('OAR') }]),
+    oar: new FileSignature('.oar', [{ value: Buffer.from('OAR') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.rar', [{ value: Buffer.from('Rar!\x1A\x07\x00') }]), // v1.50+
-    new FileSignature('.rar', [{ value: Buffer.from('Rar!\x1A\x07\x01\x00') }]), // v5.00+
+    rar1: new FileSignature('.rar', [{ value: Buffer.from('Rar!\x1A\x07\x00') }]), // v1.50+
+    rar5: new FileSignature('.rar', [{ value: Buffer.from('Rar!\x1A\x07\x01\x00') }]), // v5.00+
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.rs', [{ value: Buffer.from('RSVKDATA') }]),
+    rs: new FileSignature('.rs', [{ value: Buffer.from('RSVKDATA') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.tar', [{ offset: 257, value: Buffer.from('ustar\x0000') }]),
-    new FileSignature('.tar', [{ offset: 257, value: Buffer.from('ustar\x20\x20\x00') }]),
+    tar1: new FileSignature('.tar', [{ offset: 257, value: Buffer.from('ustar\x0000') }]),
+    tar2: new FileSignature('.tar', [{ offset: 257, value: Buffer.from('ustar\x20\x20\x00') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.xar', [{ value: Buffer.from('xar!') }]),
+    xar: new FileSignature('.xar', [{ value: Buffer.from('xar!') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.xz', [{ value: Buffer.from('\xFD7zXZ\x00') }]),
+    xz: new FileSignature('.xz', [{ value: Buffer.from('\xFD7zXZ\x00') }]),
     // .tar.xz has the same file signature
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.z', [{ value: Buffer.from('1F9D', 'hex') }]), // LZW compression
-    new FileSignature('.z', [{ value: Buffer.from('1FA0', 'hex') }]), // LZH compression
+    z_lzw: new FileSignature('.z', [{ value: Buffer.from('1F9D', 'hex') }]), // LZW compression
+    z_lzh: new FileSignature('.z', [{ value: Buffer.from('1FA0', 'hex') }]), // LZH compression
     // .tar.z has the same file signature
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.zip', [{ value: Buffer.from('PK\x03\x04') }]),
-    new FileSignature('.zip', [{ value: Buffer.from('PK\x05\x06') }]), // empty archive
+    zip: new FileSignature('.zip', [{ value: Buffer.from('PK\x03\x04') }]),
+    zip_empty: new FileSignature('.zip', [{ value: Buffer.from('PK\x05\x06') }]), // empty archive
     // .zipx has the same file signature?
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.zst', [{ value: Buffer.from('28B52FFD', 'hex') }]),
+    zst: new FileSignature('.zst', [{ value: Buffer.from('28B52FFD', 'hex') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.z01', [{ value: Buffer.from('PK\x07\x08') }]),
+    z01: new FileSignature('.z01', [{ value: Buffer.from('PK\x07\x08') }]),
 
     // ********** ROMs - GENERAL **********
 
     // @see https://docs.fileformat.com/disc-and-media/cso/
-    new FileSignature('.cso', [{ value: Buffer.from('CISO') }]),
+    cso: new FileSignature('.cso', [{ value: Buffer.from('CISO') }]),
 
     // @see https://en.wikipedia.org/wiki/List_of_file_signatures
-    new FileSignature('.isz', [{ value: Buffer.from('IsZ!') }]),
+    isz: new FileSignature('.isz', [{ value: Buffer.from('IsZ!') }]),
 
     // @see https://docs.fileformat.com/disc-and-media/cso/
-    new FileSignature('.zso', [{ value: Buffer.from('ZISO') }]),
+    zso: new FileSignature('.zso', [{ value: Buffer.from('ZISO') }]),
 
     // ********** ROMs - SPECIFIC **********
 
     // Atari - 7800
-    new FileSignature('.a78', [{ offset: 1, value: Buffer.from('ATARI7800') }]),
+    a78: new FileSignature('.a78', [{ offset: 1, value: Buffer.from('ATARI7800') }]),
 
     // Atari - Lynx
-    new FileSignature('.lnx', [{ value: Buffer.from('LYNX') }]),
+    lnx: new FileSignature('.lnx', [{ value: Buffer.from('LYNX') }]),
 
     // Nintendo - Nintendo 3DS
-    new FileSignature('.3dsx', [{ value: Buffer.from('3DSX') }]),
+    '3dsx': new FileSignature('.3dsx', [{ value: Buffer.from('3DSX') }]),
 
     // Nintendo - Nintendo 64
     // @see http://n64dev.org/romformats.html
-    new FileSignature('.n64', [{ value: Buffer.from('40123780', 'hex') }]), // little endian
-    new FileSignature('.v64', [{ value: Buffer.from('37804012', 'hex') }]), // byte-swapped
-    new FileSignature('.z64', [{ value: Buffer.from('80371240', 'hex') }]), // native
+    n64: new FileSignature('.n64', [{ value: Buffer.from('40123780', 'hex') }]), // little endian
+    v64: new FileSignature('.v64', [{ value: Buffer.from('37804012', 'hex') }]), // byte-swapped
+    z64: new FileSignature('.z64', [{ value: Buffer.from('80371240', 'hex') }]), // native
 
     // Nintendo - Nintendo 64 Disk Drive
-    new FileSignature('.ndd', [{ value: Buffer.from('E848D31610', 'hex') }]),
+    ndd: new FileSignature('.ndd', [{ value: Buffer.from('E848D31610', 'hex') }]),
 
     // Nintendo - Famicom Disk System
-    new FileSignature('.fds', [{ value: Buffer.from('\x01*NINTENDO-HVC*') }]),
-    new FileSignature('.fds', [{ value: Buffer.from('FDS') }]),
+    fds_hvc: new FileSignature('.fds', [{ value: Buffer.from('\x01*NINTENDO-HVC*') }]),
+    fds: new FileSignature('.fds', [{ value: Buffer.from('FDS') }]),
 
     // Nintendo - Game & Watch
-    new FileSignature('.bin', [{ value: Buffer.from('main.bs') }]),
+    gw: new FileSignature('.bin', [{ value: Buffer.from('main.bs') }]),
 
     // Nintendo - Game Boy
     // @see https://gbdev.io/pandocs/The_Cartridge_Header.html
-    new FileSignature('.gb', [
+    gb: new FileSignature('.gb', [
       { offset: 0x01_04, value: Buffer.from('CEED6666CC0D000B03730083000C000D0008111F8889000EDCCC6EE6DDDDD999BBBB67636E0EECCCDDDC999FBBB9333E', 'hex') }, // logo
       { offset: 0x01_43, value: Buffer.from('00', 'hex') }, // non-color
     ]),
 
     // Nintendo - Game Boy Advance
     // @see http://problemkaputt.de/gbatek.htm#gbacartridges
-    new FileSignature('.gba', [{ offset: 0x04, value: Buffer.from('24FFAE51699AA2213D84820A84E409AD11248B98C0817F21A352BE199309CE2010464A4AF82731EC58C7E83382E3CEBF85F4DF94CE4B09C194568AC01372A7FC9F844D73A3CA9A615897A327FC039876231DC7610304AE56BF38840040A70EFDFF52FE036F9530F197FBC08560D68025A963BE03014E38E2F9A234FFBB3E0344780090CB88113A9465C07C6387F03CAFD625E48B380AAC7221D4F807', 'hex') }]), // logo
+    gba: new FileSignature('.gba', [{ offset: 0x04, value: Buffer.from('24FFAE51699AA2213D84820A84E409AD11248B98C0817F21A352BE199309CE2010464A4AF82731EC58C7E83382E3CEBF85F4DF94CE4B09C194568AC01372A7FC9F844D73A3CA9A615897A327FC039876231DC7610304AE56BF38840040A70EFDFF52FE036F9530F197FBC08560D68025A963BE03014E38E2F9A234FFBB3E0344780090CB88113A9465C07C6387F03CAFD625E48B380AAC7221D4F807', 'hex') }]), // logo
 
     // Nintendo - Game Boy Color
     // @see https://gbdev.io/pandocs/The_Cartridge_Header.html
-    new FileSignature('.gbc', [
+    gb_dx: new FileSignature('.gbc', [
       { offset: 0x01_04, value: Buffer.from('CEED6666CC0D000B03730083000C000D0008111F8889000EDCCC6EE6DDDDD999BBBB67636E0EECCCDDDC999FBBB9333E', 'hex') }, // logo
       { offset: 0x01_43, value: Buffer.from('80', 'hex') }, // backwards compatible
     ]),
-    new FileSignature('.gbc', [
+    gbc: new FileSignature('.gbc', [
       { offset: 0x01_04, value: Buffer.from('CEED6666CC0D000B03730083000C000D0008111F8889000EDCCC6EE6DDDDD999BBBB67636E0EECCCDDDC999FBBB9333E', 'hex') }, // logo
       { offset: 0x01_43, value: Buffer.from('C0', 'hex') }, // color only
     ]),
 
     // Nintendo - Nintendo DS (Decrypted)
     // @see http://dsibrew.org/wiki/DSi_cartridge_header
-    new FileSignature('.nds', [
+    nds: new FileSignature('.nds', [
       { offset: 0xC0, value: Buffer.from('24FFAE51699AA2213D84820A84E409AD11248B98C0817F21A352BE199309CE2010464A4AF82731EC58C7E83382E3CEBF85F4DF94CE4B09C194568AC01372A7FC9F844D73A3CA9A615897A327FC039876231DC7610304AE56BF38840040A70EFDFF52FE036F9530F197FBC08560D68025A963BE03014E38E2F9A234FFBB3E0344780090CB88113A9465C07C6387F03CAFD625E48B380AAC7221D4F807') }, // logo
       { offset: 0x1_5C, value: Buffer.from('56CF', 'hex') }, // logo checksum
     ]),
 
     // Nintendo - Nintendo Entertainment System
-    new FileSignature('.nes', [{ value: Buffer.from('NES') }]),
+    nes: new FileSignature('.nes', [{ value: Buffer.from('NES') }]),
 
     // Nintendo - Super Nintendo Entertainment System
     // @see https://snes.nesdev.org/wiki/ROM_header
     // @see https://en.wikibooks.org/wiki/Super_NES_Programming/SNES_memory_map
     // TODO(cemmer): add checks from LoROM, HiROM, etc.
-    new FileSignature('.smc', [{ offset: 3, value: Buffer.from('00'.repeat(509), 'hex') }]),
+    smc: new FileSignature('.smc', [{ offset: 3, value: Buffer.from('00'.repeat(509), 'hex') }]),
     // @see https://file-extension.net/seeker/file_extension_smc
     // @see https://wiki.superfamicom.org/game-doctor
-    new FileSignature('.smc', [{ value: Buffer.from('\x00\x01ME DOCTOR SF 3') }]), // Game Doctor SF3?
-    new FileSignature('.smc', [{ value: Buffer.from('GAME DOCTOR SF 3') }]), // Game Doctor SF3/SF6/SF7
+    smc_gd3_1: new FileSignature('.smc', [{ value: Buffer.from('\x00\x01ME DOCTOR SF 3') }]), // Game Doctor SF3?
+    smc_gd3_2: new FileSignature('.smc', [{ value: Buffer.from('GAME DOCTOR SF 3') }]), // Game Doctor SF3/SF6/SF7
 
     // Sega - 32X
     // @see https://github.com/jcfieldsdev/genesis-rom-utility/blob/31826bca66c8c6c467c37c1b711943eb5464e7e8/genesis_rom.chm
     // @see https://plutiedev.com/rom-header
-    new FileSignature('.32x', [{ offset: 0x1_00, value: Buffer.from('SEGA 32X') }]),
+    '32x': new FileSignature('.32x', [{ offset: 0x1_00, value: Buffer.from('SEGA 32X') }]),
 
     // Sega - Game Gear
     // @see https://gbatemp.net/threads/help-with-rom-iso-console-identification.611378/
-    new FileSignature('.gg', [{ offset: 0x7F_F0, value: Buffer.from('TMR SEGA') }]),
+    gg: new FileSignature('.gg', [{ offset: 0x7F_F0, value: Buffer.from('TMR SEGA') }]),
 
     // Sega - Mega Drive / Genesis
     // @see https://github.com/jcfieldsdev/genesis-rom-utility/blob/31826bca66c8c6c467c37c1b711943eb5464e7e8/genesis_rom.chm
     // @see https://plutiedev.com/rom-header
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA            ') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA IS A REGISTERED') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA IS A TRADEMARK ') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA GENESIS') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from(' SEGA GENESIS') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA_GENESIS') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA MEGADRIVE') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA MEGA DRIVE') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from(' SEGA MEGA DRIVE') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA_MEGA_DRIVE') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from(' SEGA_MEGA_DRIVE') }]),
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGASEGASEGA') }]),
+    md_1: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA            ') }]),
+    md_2: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA IS A REGISTERED') }]),
+    md_3: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA IS A TRADEMARK ') }]),
+    md_4: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA GENESIS') }]),
+    md_5: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from(' SEGA GENESIS') }]),
+    md_6: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA_GENESIS') }]),
+    md_7: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA MEGADRIVE') }]),
+    md_8: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA MEGA DRIVE') }]),
+    md_9: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from(' SEGA MEGA DRIVE') }]),
+    md_10: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA_MEGA_DRIVE') }]),
+    md_11: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from(' SEGA_MEGA_DRIVE') }]),
+    md_12: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGASEGASEGA') }]),
     // @see https://www.romhacking.net/forum/index.php?topic=32880.msg415017#msg415017
-    new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAGNSS  ') }]),
-    new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAMG RV') }]),
-    new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAMG_RV') }]),
-    new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAMGDIE') }]),
-    new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('SG EEI  ') }]),
+    smd_1: new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAGNSS  ') }]),
+    smd_2: new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAMG RV') }]),
+    smd_3: new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAMG_RV') }]),
+    smd_4: new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('EAMGDIE') }]),
+    smd_5: new FileSignature('.smd', [{ offset: 0x2_80, value: Buffer.from('SG EEI  ') }]),
 
     // Sega - PICO
     // @see https://github.com/jcfieldsdev/genesis-rom-utility/blob/31826bca66c8c6c467c37c1b711943eb5464e7e8/genesis_rom.chm
     // @see https://plutiedev.com/rom-header
-    new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA PICO') }]),
+    pico: new FileSignature('.md', [{ offset: 0x1_00, value: Buffer.from('SEGA PICO') }]),
 
     // Sony - PlayStation Portable
-    new FileSignature('.pbp', [{ value: Buffer.from('\x00PBP\x00\x00\x01\x00') }]),
-  ].sort((a, b) => {
-    // 1. Prefer files that check multiple signatures
-    const sigsCountDiff = b.fileSignatures.length - a.fileSignatures.length;
-    if (sigsCountDiff !== 0) {
-      return sigsCountDiff;
-    }
+    pbp: new FileSignature('.pbp', [{ value: Buffer.from('\x00PBP\x00\x00\x01\x00') }]),
+  };
+
+  private static readonly SIGNATURES_SORTED = Object.values(FileSignature.SIGNATURES)
+    .sort((a, b) => {
+      // 1. Prefer files that check multiple signatures
+      const sigsCountDiff = b.fileSignatures.length - a.fileSignatures.length;
+      if (sigsCountDiff !== 0) {
+        return sigsCountDiff;
+      }
 
-    // 2. Prefer signatures of longer length
-    return b.fileSignatures.reduce((sum, sig) => sum + sig.value.length, 0)
-      - a.fileSignatures.reduce((sum, sig) => sum + sig.value.length, 0);
-  });
+      // 2. Prefer signatures of longer length
+      return b.fileSignatures.reduce((sum, sig) => sum + sig.value.length, 0)
+        - a.fileSignatures.reduce((sum, sig) => sum + sig.value.length, 0);
+    });
 
   private static readonly MAX_HEADER_LENGTH_BYTES = Object.values(FileSignature.SIGNATURES)
     .flatMap((romSignature) => romSignature.fileSignatures)
@@ -221,6 +226,10 @@ export default class FileSignature {
     this.fileSignatures = fileSignatures;
   }
 
+  static getKnownSignatureCount(): number {
+    return this.SIGNATURES_SORTED.length;
+  }
+
   private static async readHeaderBuffer(
     stream: Readable,
     start: number,
@@ -251,11 +260,15 @@ export default class FileSignature {
     });
   }
 
+  static signatureFromName(name: string): FileSignature | undefined {
+    return this.SIGNATURES[name];
+  }
+
   static async signatureFromFileStream(stream: Readable): Promise<FileSignature | undefined> {
     const fileHeader = await FileSignature
       .readHeaderBuffer(stream, 0, this.MAX_HEADER_LENGTH_BYTES);
 
-    for (const romSignature of this.SIGNATURES) {
+    for (const romSignature of this.SIGNATURES_SORTED) {
       const signatureMatch = romSignature.fileSignatures.every((fileSignature) => {
         const signatureValue = fileHeader.subarray(
           fileSignature.offset ?? 0,
@@ -271,6 +284,12 @@ export default class FileSignature {
     return undefined;
   }
 
+  @Memoize()
+  getName(): string {
+    return Object.keys(FileSignature.SIGNATURES)
+      .find((name) => FileSignature.SIGNATURES[name] === this) as string;
+  }
+
   getExtension(): string {
     return this.extension;
   }
diff --git a/src/types/files/romHeader.ts b/src/types/files/romHeader.ts
index 1f4d04681..7fda49b5d 100644
--- a/src/types/files/romHeader.ts
+++ b/src/types/files/romHeader.ts
@@ -6,7 +6,7 @@ import { Memoize } from 'typescript-memoize';
 import ArrayPoly from '../../polyfill/arrayPoly.js';
 
 export default class ROMHeader {
-  private static readonly HEADERS: { [key: string]:ROMHeader } = {
+  private static readonly HEADERS: { [key: string]: ROMHeader } = {
     // http://7800.8bitdev.org/index.php/A78_Header_Specification
     'No-Intro_A7800.xml': new ROMHeader(1, '415441524937383030', 128, '.a78'),
 
@@ -64,6 +64,10 @@ export default class ROMHeader {
       .sort();
   }
 
+  static getKnownHeaderCount(): number {
+    return Object.keys(this.HEADERS).length;
+  }
+
   static headerFromName(name: string): ROMHeader | undefined {
     return this.HEADERS[name];
   }