Mock client IDs for testing & demos
Generate realistic client ID numbers instantly — prefixed codes, hex strings, UUID-style values and plain numerics. Set the count, format, prefix and length, then copy or download the set. Everything runs 100% in your browser — no sign-up, no server, nothing stored.
IDs are deduplicated within each generated batch.
Prefixed codes read best in UIs; UUIDs suit database-style test data.
Longer random parts make accidental collisions far less likely.
Letters and digits only, e.g. CLT, CUST, ACME.
Your client IDs will appear here. Click any ID to copy it individually.
Honest limits — read before you use these
- These are randomly generated mock IDs for testing, demos and documentation only. They identify no real person, company or account.
- They are NOT official customer identifiers. Real systems assign their own IDs; these strings exist only in your browser tab.
- Uniqueness is only checked within the batch you just generated. The tool keeps no memory between visits, so the same ID could theoretically appear in a later batch — always enforce uniqueness in your own database with a primary key or unique constraint.
- Safe uses: seeding test databases, building and testing CRM-style interfaces, creating realistic demo data and screenshots, practicing data imports.
How it works
Secure randomness, zero servers
A small JavaScript file builds every ID on your device. No accounts, no network calls, no fine print.
Cryptographically secure randomness
Each character is drawn with crypto.getRandomValues() using rejection sampling to avoid modulo bias — the same API security-sensitive web apps rely on.
Nothing leaves your device
Generation, copying and the .txt download all happen locally in your browser tab. No backend, no database, no analytics. Close the tab and the IDs are gone.
Five formats, your prefix
Prefixed alphanumeric or numeric codes, hex strings, UUID v4 style, or plain numerics — with a custom prefix and adjustable random-part length for the prefixed styles.
Use & limits
When mock client IDs shine
One honest job: realistic-looking identifiers that identify nothing real.
Testing CRM-style software
Building a customer database, import flow or admin panel? Seed it with generated IDs and test lookups, joins and exports with data that looks like production.
Demos and documentation
Show a client list, write an API tutorial or screenshot a dashboard with believable IDs — without exposing any real customer's identifier.
Production customer keys
These IDs are random strings from your browser. Real systems need IDs issued and guaranteed unique by the system itself. Never treat mock IDs as real records.
New to client identifiers?
Learn what a client ID is, why names make terrible keys, and how real systems keep identifiers unique.
FAQ
Quick answers
What is a client ID? +
A client ID is a unique identifier assigned to each customer or client record in a system — a CRM, billing tool or database. It stays stable even when names, emails or addresses change, so the system can always tell records apart. Full guide: what is a client ID.
Can I use these IDs in a real database? +
Only as test fixtures. ClientCipher IDs are random mock strings with no uniqueness guarantee beyond the current batch. Real databases should generate their own keys (auto-increment, sequences or UUIDs) with a unique constraint.
Is the generator really private? +
Yes. Plain JavaScript in your browser using crypto.getRandomValues(). Nothing is sent over the network, no cookies are set and nothing is stored. See our privacy page.
What ID formats can I generate? +
Prefixed alphanumeric (CLT-8X4K2Q), prefixed numeric (CLT-004231), hex strings, UUID v4 style, and plain numerics — with a custom prefix and 6/8/12-character random parts. See client ID formats for when to use each.
Why not use customer names as IDs? +
Names are not unique (two customers can share one) and they change (marriage, rebranding, typos). A stable synthetic ID avoids both problems — that is the standard practice described in our unique ID guide.
Guides
Client ID guides
What client IDs are, the formats they come in, and how to design identifier schemes that stay unique.
What is a client ID?
Stable identifiers vs names, where client IDs live in CRMs and billing systems, and what makes a good one.
Read guide GuideClient ID formats
Sequential numbers, prefixed codes, hex, UUIDs — the trade-offs of each style and when to pick it.
Read guide GuideCreating unique client IDs
Auto-increment, sequences, UUIDs and random codes: how real systems guarantee uniqueness.
Read guide