diff --git a/.changeset/sour-feet-smile.md b/.changeset/sour-feet-smile.md
new file mode 100644
index 0000000000..a7633222fa
--- /dev/null
+++ b/.changeset/sour-feet-smile.md
@@ -0,0 +1,6 @@
+---
+"rrweb-snapshot": minor
+"rrdom": minor
+---
+
+improve tagName resolution
diff --git a/packages/rrdom/src/index.ts b/packages/rrdom/src/index.ts
index 577811766b..c705402a7e 100644
--- a/packages/rrdom/src/index.ts
+++ b/packages/rrdom/src/index.ts
@@ -208,7 +208,7 @@ function getValidTagName(element: HTMLElement): string {
   if (element instanceof HTMLFormElement) {
     return 'FORM';
   }
-  return element.tagName.toUpperCase();
+  return element.tagName;
 }
 
 /**
diff --git a/packages/rrweb-snapshot/src/snapshot.ts b/packages/rrweb-snapshot/src/snapshot.ts
index cd3d7189b7..7e7a4adbf2 100644
--- a/packages/rrweb-snapshot/src/snapshot.ts
+++ b/packages/rrweb-snapshot/src/snapshot.ts
@@ -41,6 +41,12 @@ export function genId(): number {
 }
 
 function getValidTagName(element: HTMLElement): Lowercase<string> {
+  const commonTagName = HTML_TAGNAMES[element.tagName];
+  if (commonTagName) {
+    return commonTagName;
+  }
+
+  // https://github.com/rrweb-io/rrweb-snapshot/issues/56
   if (element instanceof HTMLFormElement) {
     return 'form';
   }
@@ -57,6 +63,158 @@ function getValidTagName(element: HTMLElement): Lowercase<string> {
   return processedTagName;
 }
 
+const HTML_TAGNAMES: Record<string, Lowercase<string>> = {
+  A: 'a',
+  ABBR: 'abbr',
+  ACRONYM: 'acronym',
+  ADDRESS: 'address',
+  APPLET: 'applet',
+  AREA: 'area',
+  ARTICLE: 'article',
+  ASIDE: 'aside',
+  AUDIO: 'audio',
+  B: 'b',
+  BASE: 'base',
+  BASEFONT: 'basefont',
+  BDI: 'bdi',
+  BDO: 'bdo',
+  BGSOUND: 'bgsound',
+  BIG: 'big',
+  BLINK: 'blink',
+  BLOCKQUOTE: 'blockquote',
+  BODY: 'body',
+  BR: 'br',
+  BUTTON: 'button',
+  CANVAS: 'canvas',
+  CAPTION: 'caption',
+  CENTER: 'center',
+  CITE: 'cite',
+  CODE: 'code',
+  COL: 'col',
+  COLGROUP: 'colgroup',
+  COMMAND: 'command',
+  CONTENT: 'content',
+  DATA: 'data',
+  DATALIST: 'datalist',
+  DD: 'dd',
+  DEL: 'del',
+  DETAILS: 'details',
+  DFN: 'dfn',
+  DIALOG: 'dialog',
+  DIR: 'dir',
+  DIV: 'div',
+  DL: 'dl',
+  DT: 'dt',
+  ELEMENT: 'element',
+  EM: 'em',
+  EMBED: 'embed',
+  FIELDSET: 'fieldset',
+  FIGCAPTION: 'figcaption',
+  FIGURE: 'figure',
+  FONT: 'font',
+  FOOTER: 'footer',
+  FORM: 'form',
+  FRAME: 'frame',
+  FRAMESET: 'frameset',
+  H1: 'h1',
+  H2: 'h2',
+  H3: 'h3',
+  H4: 'h4',
+  H5: 'h5',
+  H6: 'h6',
+  HEAD: 'head',
+  HEADER: 'header',
+  HGROUP: 'hgroup',
+  HR: 'hr',
+  HTML: 'html',
+  I: 'i',
+  IFRAME: 'iframe',
+  IMAGE: 'image',
+  IMG: 'img',
+  INPUT: 'input',
+  INS: 'ins',
+  ISINDEX: 'isindex',
+  KBD: 'kbd',
+  KEYGEN: 'keygen',
+  LABEL: 'label',
+  LEGEND: 'legend',
+  LI: 'li',
+  LINK: 'link',
+  LISTING: 'listing',
+  MAIN: 'main',
+  MAP: 'map',
+  MARK: 'mark',
+  MARQUEE: 'marquee',
+  MATH: 'math',
+  MENU: 'menu',
+  MENUITEM: 'menuitem',
+  META: 'meta',
+  METER: 'meter',
+  MULTICOL: 'multicol',
+  NAV: 'nav',
+  NEXTID: 'nextid',
+  NOBR: 'nobr',
+  NOEMBED: 'noembed',
+  NOFRAMES: 'noframes',
+  NOSCRIPT: 'noscript',
+  OBJECT: 'object',
+  OL: 'ol',
+  OPTGROUP: 'optgroup',
+  OPTION: 'option',
+  OUTPUT: 'output',
+  P: 'p',
+  PARAM: 'param',
+  PICTURE: 'picture',
+  PLAINTEXT: 'plaintext',
+  PRE: 'pre',
+  PROGRESS: 'progress',
+  Q: 'q',
+  RB: 'rb',
+  RBC: 'rbc',
+  RP: 'rp',
+  RT: 'rt',
+  RTC: 'rtc',
+  RUBY: 'ruby',
+  S: 's',
+  SAMP: 'samp',
+  SCRIPT: 'script',
+  SEARCH: 'search',
+  SECTION: 'section',
+  SELECT: 'select',
+  SHADOW: 'shadow',
+  SLOT: 'slot',
+  SMALL: 'small',
+  SOURCE: 'source',
+  SPACER: 'spacer',
+  SPAN: 'span',
+  STRIKE: 'strike',
+  STRONG: 'strong',
+  STYLE: 'style',
+  SUB: 'sub',
+  SUMMARY: 'summary',
+  SUP: 'sup',
+  SVG: 'svg',
+  TABLE: 'table',
+  TBODY: 'tbody',
+  TD: 'td',
+  TEMPLATE: 'template',
+  TEXTAREA: 'textarea',
+  TFOOT: 'tfoot',
+  TH: 'th',
+  THEAD: 'thead',
+  TIME: 'time',
+  TITLE: 'title',
+  TR: 'tr',
+  TRACK: 'track',
+  TT: 'tt',
+  U: 'u',
+  UL: 'ul',
+  VAR: 'var',
+  VIDEO: 'video',
+  WBR: 'wbr',
+  XMP: 'xmp',
+};
+
 let canvasService: HTMLCanvasElement | null;
 let canvasCtx: CanvasRenderingContext2D | null;