(function(){var H=function(n,l){return n.toString(16).padStart(l,'0');};var R=function(n){var b=new Uint8Array(n);crypto.getRandomValues(b);return b;};var F=function(b){return[b.slice(0,4),b.slice(4,6),b.slice(6,8),b.slice(8,10),b.slice(10,16)].map(function(s){return Array.from(s).map(function(x){return H(x,2);}).join('');}).join('-');};function g4(){var b=R(16);b[6]=(b[6]&15)|64;b[8]=(b[8]&63)|128;return F(b);}function g7(){var ms=BigInt(Date.now()),b=R(16);b[0]=Number((ms>>40n)&255n);b[1]=Number((ms>>32n)&255n);b[2]=Number((ms>>24n)&255n);b[3]=Number((ms>>16n)&255n);b[4]=Number((ms>>8n)&255n);b[5]=Number(ms&255n);b[6]=(b[6]&15)|112;b[8]=(b[8]&63)|128;return F(b);}function g6(){var n=BigInt(Date.now())*10000n+122192928000000000n,b=R(16),t=Number((n>>28n)%281474976710656n),L=Number(n%4096n);b[0]=(t>>40)&255;b[1]=(t>>32)&255;b[2]=(t>>24)&255;b[3]=(t>>16)&255;b[4]=(t>>8)&255;b[5]=t&255;b[6]=(Math.floor(t/256)&15)|96;b[7]=L&255;b[8]=(b[8]&63)|128;return F(b);}function g1(){var n=BigInt(Date.now())*10000n+122192928000000000n,tL=Number(n%4294967296n),tM=Number((n>>32n)%65536n),tH=Number((n>>48n)%4096n)|4096,b=R(10),cs=((b[0]&63)<<8|b[1])|32768;return H(tL,8)+'-'+H(tM,4)+'-'+H(tH,4)+'-'+H(cs,4)+'-'+Array.from(b.slice(2,8)).map(function(x){return H(x,2);}).join('');}function g8(){var b=R(16);b[6]=(b[6]&15)|128;b[8]=(b[8]&63)|128;return F(b);}async function g5(ns,nm){var nh=ns.replace(/-/g,''),nb=new Uint8Array(nh.match(/../g).map(function(h){return parseInt(h,16);})),nmb=new TextEncoder().encode(nm),c=new Uint8Array(nb.length+nmb.length);c.set(nb);c.set(nmb,nb.length);var h=new Uint8Array(await crypto.subtle.digest('SHA-1',c)).slice(0,16);h[6]=(h[6]&15)|80;h[8]=(h[8]&63)|128;return F(h);}function vl(s){s=s.trim().toLowerCase();var r=/^[0-9a-f]{8}-[0-9a-f]{4}-([1-8])[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/;if(s==='00000000-0000-0000-0000-000000000000')return{ok:true,ver:'Nil UUID'};if(s==='ffffffff-ffff-ffff-ffff-ffffffffffff')return{ok:true,ver:'Max UUID'};if(!r.test(s))return{ok:false};var vn={1:'v1',3:'v3',4:'v4 (Random)',5:'v5',6:'v6',7:'v7',8:'v8'};return{ok:true,ver:vn[s[14]]||'v'+s[14]};}function af(u){var uc=document.getElementById('uuid-uppercase').checked,nh=document.getElementById('uuid-no-hyphens').checked,o=uc?u.toUpperCase():u;if(nh)o=o.replace(/-/g,'');return o;}function gu(){var cv=window._ucv||'4';if(cv==='1')return g1();if(cv==='6')return g6();if(cv==='7')return g7();if(cv==='8')return g8();if(cv==='nil')return'00000000-0000-0000-0000-000000000000';if(cv==='max')return'ffffffff-ffff-ffff-ffff-ffffffffffff';return g4();}window._ucv='4';function gen(){var cv=window._ucv;if(cv==='5'){var ns=document.getElementById('uuid-ns-select'),nsv=ns.value==='custom'?document.getElementById('uuid-ns-custom').value:ns.value,nm=document.getElementById('uuid-ns-name').value||'example.com';g5(nsv,nm).then(function(u){document.getElementById('uuid-output').value=af(u);});}else{document.getElementById('uuid-output').value=af(gu());}}function toast(m){var t=document.getElementById('uuidgen-toast');if(!t){t=document.createElement('div');t.id='uuidgen-toast';t.className='utoast';document.body.appendChild(t);}t.textContent=m;t.classList.add('show');setTimeout(function(){t.classList.remove('show');},2200);}function cpOk(btn){if(btn){var o=btn.innerHTML;btn.innerHTML='Copied!';btn.classList.add('copied');setTimeout(function(){btn.innerHTML=o;btn.classList.remove('copied');},1800);}toast('Copied!');}function cp(tx,btn){if(navigator.clipboard&&navigator.clipboard.writeText){navigator.clipboard.writeText(tx).then(function(){cpOk(btn);}).catch(function(){cpFallback(tx,btn);});}else{cpFallback(tx,btn);}}function cpFallback(tx,btn){var ta=document.createElement('textarea');ta.value=tx;ta.style.position='fixed';ta.style.top='-9999px';ta.style.left='-9999px';document.body.appendChild(ta);ta.focus();ta.select();try{document.execCommand('copy');cpOk(btn);}catch(e){}document.body.removeChild(ta);}document.addEventListener('click',function(e){var t=e.target,vt=t.closest('.uvtab');if(vt){document.querySelectorAll('.uvtab').forEach(function(b){b.classList.remove('active');b.ariaSelected='false';});vt.classList.add('active');vt.ariaSelected='true';window._ucv=vt.dataset.v;var nf=document.getElementById('uuid-ns-fields');if(window._ucv==='3'||window._ucv==='5')nf.classList.add('vis');else nf.classList.remove('vis');gen();return;}if(t.closest('#uuid-generate-btn')){gen();return;}if(t.closest('#uuid-copy-btn')){var v=document.getElementById('uuid-output').value;if(v&&v!=='Click Generate or choose a version')cp(v,document.getElementById('uuid-copy-btn'));return;}if(t.closest('#uuid-bulk-btn')){document.getElementById('uuid-bulk-panel').classList.toggle('open');document.getElementById('uuid-validate-panel').classList.remove('open');return;}if(t.closest('#uuid-bulk-generate-btn')){var cnt=Math.min(1000,Math.max(1,parseInt(document.getElementById('uuid-bulk-count').value)||10)),fm=document.getElementById('uuid-bulk-format').value,uuids=[],i;for(i=0;i<cnt;i++)uuids.push(af(gu()));var NL=String.fromCharCode(10),out=fm==='json'?JSON.stringify(uuids,null,2):fm==='csv'?uuids.join(','+NL):uuids.join(NL);document.getElementById('uuid-bulk-output').textContent=out;return;}if(t.closest('#uuid-bulk-copy-btn')){var txt=document.getElementById('uuid-bulk-output').textContent;if(txt)cp(txt,document.getElementById('uuid-bulk-copy-btn'));return;}if(t.closest('#uuid-bulk-download-btn')){var tx2=document.getElementById('uuid-bulk-output').textContent,fm2=document.getElementById('uuid-bulk-format').value,ext=fm2==='json'?'json':fm2==='csv'?'csv':'txt',bl=new Blob([tx2],{type:'text/plain'}),a=document.createElement('a');a.href=URL.createObjectURL(bl);a.download='uuids.'+ext;a.click();return;}if(t.closest('#uuid-validate-btn')){document.getElementById('uuid-validate-panel').classList.toggle('open');document.getElementById('uuid-bulk-panel').classList.remove('open');if(document.getElementById('uuid-validate-panel').classList.contains('open'))setTimeout(function(){document.getElementById('uuid-validate-input').focus();},100);return;}var fq=t.closest('.ufaq-q');if(fq){var item=fq.closest('.ufaq-item'),was=item.classList.contains('open');document.querySelectorAll('.ufaq-item').forEach(function(i){i.classList.remove('open');i.querySelector('.ufaq-q').setAttribute('aria-expanded','false');});if(!was){item.classList.add('open');fq.setAttribute('aria-expanded','true');}return;}});document.addEventListener('change',function(e){var t=e.target;if(t.id==='uuid-ns-select')document.getElementById('uuid-ns-custom-wrap').style.display=t.value==='custom'?'block':'none';if(t.id==='uuid-uppercase'||t.id==='uuid-no-hyphens'){var cur=document.getElementById('uuid-output').value;if(cur&&cur!=='Click Generate or choose a version'){var base=cur.replace(/-/g,'').toLowerCase();if(base.length===32)base=base.replace(/(.{8})(.{4})(.{4})(.{4})(.{12})/,'$1-$2-$3-$4-$5');document.getElementById('uuid-output').value=af(base);}}});document.addEventListener('input',function(e){if(e.target.id!=='uuid-validate-input')return;var r=vl(e.target.value),el=document.getElementById('uuid-validate-result');if(!e.target.value.trim()){el.style.display='none';return;}el.style.display='block';if(r.ok){el.style.background='var(--ugl)';el.style.color='var(--ug)';el.style.border='1.5px solid #86efac';el.textContent='Valid - '+r.ver;}else{el.style.background='var(--url)';el.style.color='var(--ur)';el.style.border='1.5px solid #fca5a5';el.textContent='Invalid - check 8-4-4-4-12 hex format';}});if(document.readyState==='loading'){document.addEventListener('DOMContentLoaded',gen);}else{setTimeout(gen,0);}})();
Generate GUID →
itemtype=”https://schema.org/FAQPage”>
RFC 9562 Compliant · All 8 Versions
UUID Generator
Generate random UUIDs instantly — v1, v4, v7, and all 8 versions including UUIDv4, UUIDv7, GUID, and Nil. Bulk export, validate, and decode. Runs entirely in your browser — your random UUID generator with zero server calls.
Only need one version? Try the dedicated UUID v4 or UUID v7 generator.
Bulk Generation
Validate UUID
★ 100% Free & Online
✓ No Signup
🔒 Browser-Only · Zero Server Calls
★ RFC 9562 Compliant
The Basics
What is a UUID?
A UUID (Universally Unique Identifier), also called a GUID (Globally Unique Identifier) in Microsoft/.NET contexts, is a 128-bit number used to generate a unique, random ID for any resource — a database row, API object, session, or file — without any central authority handing out IDs. Any computer can independently generate a random UUID or random GUID and trust it will not collide with an identifier generated anywhere else.
Every UUID is 32 hexadecimal digits in an 8-4-4-4-12 pattern — 36 characters total:
f47ac10b-58cc-4372-a567-0e02b2c3d479
RFC 4122 (2005) introduced versions 1–5. RFC 9562 (May 2024) superseded it and formally added v6, v7, and v8. You will also see the term GUID (Globally Unique Identifier) in Microsoft/.NET contexts — it is the same standard with a byte-order difference in some implementations.
Microsoft / .NET / COM
Need a GUID Generator?
Generate a new GUID online — same 128-bit standard, .NET & COM byte-order framing. Free, instant, browser-only.
Version Guide
Which UUID version should you use?
UUID v7 (UUIDv7) is now the recommended default for database primary keys — it embeds a millisecond Unix timestamp so IDs sort by creation time and index far more efficiently in a B-tree than a random ID. PostgreSQL 18 ships native uuidv7() support. UUID v4 (UUIDv4, uuid4) remains the right pick for opaque tokens, random IDs, and secrets where you do not want to expose creation time. Need a new GUID instead? Select v4 above — a GUID and a UUID v4 are the same 128-bit random identifier.
| Version | Based On | Time-Sortable | Best For | Status |
|---|---|---|---|---|
| v1 | Timestamp + MAC | Partially | Legacy distributed systems | Avoid (MAC leak) |
| v3 | Namespace + name (MD5) | No | Deterministic IDs, legacy | Use v5 instead |
| v4 | 122 bits random | No | Tokens, secrets, random IDs, GUIDs (UUIDv4, uuid4) | Recommended |
| v5 | Namespace + name (SHA-1) | No | Deterministic, reproducible IDs | Recommended |
| v6 | Reordered timestamp + random | Yes | v1 migration path | RFC 9562 |
| v7 | Unix ms timestamp + random | Yes | Database primary keys (UUIDv7, uuid7) | Recommended 2026 |
| v8 | Custom layout | Depends | Application-defined schemas | Experimental |
| Nil / Max | All-zero / all-F | — | Placeholders and testing | Special values |
v1–v5 defined in RFC 4122 (2005). v6, v7, and v8 defined in RFC 9562 (May 2024).
Use Cases
What are UUIDs used for?
UUIDs are the default unique ID generator solution anywhere a system needs collision-free random IDs without central coordination — the foundation of modern distributed software. A UUID is also the format behind every GUID, random ID, and randomly generated identifier across the web.
🖺
Database Primary Keys
Unique row identifiers that work across shards and replicas without a shared sequence generator.
🔗
API Resource IDs
REST and GraphQL object identifiers that do not expose sequential counts to clients.
⚡
Distributed Systems
Microservices and offline-first apps can generate IDs independently with no database round-trip.
🔒
Session Tracking
Session tokens, request IDs, and trace IDs across logs and distributed tracing systems.
📁
File Naming
Collision-free names for uploads, generated assets, and object storage buckets.
🧪
Test & Mock Data
Collision-free placeholder IDs, random ID generator output for test suites, and database seed data.
Collision Probability
How unique is a UUID, really?
A UUID v4 has 122 bits of actual randomness. That gives roughly 5.3 × 10³⁶ possible values.
5,316,911,983,139,663,491,615,228,241,121,400,000
Possible UUID v4 values. This is why UUID is the world’s most reliable random ID generator — if every person on Earth generated 600 million random IDs each, the probability of a single collision would still be around 50%.
Practically speaking, treat v4 collisions as a non-event at any realistic scale. One important caveat: a UUID is not a cryptographic secret. It is built for uniqueness, not unguessability under attack. Never use a UUID alone as an auth token or password.
Developer Reference
Generate a UUID in your language
Every major language has a native implementation to get a UUID, create a random ID, or build a unique ID generator into your own app:
🔒
This Online UUID Generator Runs Entirely in Your Browser
Every UUID produced here is created client-side using your browser’s built-in crypto.getRandomValues(). Nothing is transmitted anywhere. No UUIDs are logged, stored, or sent to any server. No account required. Open your browser’s Network tab and check for yourself.
FAQ
Frequently asked questions
Explore More Tools
Related UUID & GUID Tools
Need something specific? Each tool below is purpose-built for a distinct use case — from GUID generation for .NET developers to bulk exports for database seeding.
🔗
GUID Generator
Generate GUIDs for .NET, C#, COM, and SQL Server. Supports braces format.
✓
UUID Validator
Validate any UUID — detects version, variant bit, and format errors instantly.
📊
Bulk UUID Generator
Generate up to 10,000 UUIDs at once. Export as JSON, CSV, SQL, or plain text.
📚
What is a UUID?
Complete guide — all 8 versions, bit structure, RFC history, and when to use v4 vs v7.
UUIDs are used anywhere a system needs a unique identifier without coordinating with a central authority — database primary keys, API resource IDs, session tokens, distributed event IDs, file names, and message queue IDs are the most common applications.
They are the same 128-bit identifier standard. GUID (Globally Unique Identifier) is the term Microsoft uses in .NET, COM, and Windows implementations. Some Microsoft implementations differ in byte-order representation, but for practical purposes the terms are interchangeable.
Use UUID v7 for new database primary keys — it is time-sortable and B-tree friendly. Use UUID v4 for opaque tokens and secrets. Avoid v1 for user-facing projects because it embeds the generating machine’s MAC address.
Mathematically yes. Practically no, at any realistic scale. UUID v4 has 2 to the power of 122 possible values. To reach a 50% collision probability you would need to generate 1 billion UUIDs every second for roughly 100 years.
No. A UUID is designed for uniqueness, not cryptographic security. Do not use it as a standalone password, API secret, or auth token. Use a dedicated secret generator for anything that must be unguessable under adversarial conditions.
Yes. All versions conform to RFC 4122 (v1, v3, v4, v5) and RFC 9562 (v6, v7, v8), which superseded RFC 4122 in May 2024. The browser’s crypto.getRandomValues() API is used for all random components.
Yes — click Bulk Generate to create up to 1,000 UUIDs at once and export them as plain text, JSON, or CSV.
A UUID is 32 lowercase hexadecimal digits in five groups separated by hyphens: 8-4-4-4-12. It is always 36 characters including hyphens, or 32 without. The 13th character identifies the version; the 17th identifies the variant.