Test User-Agent Generator — Dummy UAs for Fixtures

Generate synthetic User-Agent strings for databases, log fixtures, and parser QA — generic browser templates by default, optional bot/cli preset and invalid corpus. Not a UA parser, not “what’s my UA”, not a bot-evasion guide.

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Test User-Agents — developer notes
Synthetic generic browser User-Agent strings for fixtures and parser QA. Optional bot/cli preset and invalid corpus. Not a UA parser, not bot-evasion tooling.

How generation works

Pick a quantity (1–100), kind, device class, validity, format, Client Hints export, and order. Changing an option refreshes the list immediately. Copy all or download JSON, CSV, SQL, or TXT.

Options

Quantity (1–100)
How many User-Agent strings to emit for seed jobs. Capped at 100.
Kind
Synthetic generic browser templates by default, plus documented bots/CLI, reduced documentation strings, or a custom template you own.
Device class
Desktop, mobile, or tablet layout for browser-family kinds. Hidden for common bot/cli preset.
Validity
Valid rows stay inside the selected pool. Invalid mode reveals malformed corpus kinds for negative parser tests only.
Format
Full User-Agent string, product-token emphasis, or comment-heavy legacy shape.
Client Hints
When on, JSON export adds a synthetic low-entropy Sec-CH-UA bundle aligned with the UA family — not live browser hints.
Order
Random with replacement, unique without replacement, or sequential walk. The common-bot pool has seven identities — unique/sequence errors when count exceeds the pool.

Examples

Default synthetic generic desktop

Settings

kind=syntheticGeneric, deviceClass=desktop, validity=valid

Sample output

Mozilla/5.0 (Windows NT 10.0; Win64; x64) … Chrome/120.0.0.0 …

Invalid unterminated comment

Settings

validity=invalid, invalidKind=unterminatedComment

Sample output

Mozilla/5.0 (unclosed

Related tools

Need IP or MAC fixtures or a JSON table? Try the test IP address generator, test MAC address generator, and JSON test data generator.

Test User-Agent FAQ

Fixtures, synthetic defaults, and what this tool is not

Why synthetic generic by default?

Frozen template strings avoid chasing the latest Chrome build and avoid copying a real colleague’s device fingerprint into fixtures.

I searched for a random user agent generator. Is this it?

If you need dummy User-Agent strings for fixtures and parser QA, yes. We do not ship anti-bot bypass copy or in-app social browser presets.

I searched for a fake user agent generator. Is this it?

Yes for synthetic fixture strings. No for impersonating a specific person’s browser or evading access controls.

Is this a user agent parser?

No — this mints fixture strings. Parsing pasted UAs is a different job and is not merged into this page.

Can I bypass bot detection with these strings?

No. Modern bot checks use TLS, behavior, and more than the User-Agent header alone. This tool is for fixtures and negative parser tests.

Can I use a {RANDOM} suffix in a custom template?

Yes. Append the literal {RANDOM} token to a prefix (for example MyAgent/{RANDOM}) to vary the suffix per row while keeping your fixture prefix stable.

Test Data

Synthetic field values for fixtures and DB seed — reserved-range phone numbers first.

JSON Test Data Generator

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Line-oriented JSON/NDJSON and Nginx/Apache access logs — format, filter, validate, and CSV/TSV.

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Multi-doc manifests, structural validate, Ingress/Deployment starters, and Helm values formatting.

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Count words, build Markdown TOCs, and clean line lists — all in your browser.

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