Postman is the lab.
Hit is the hammer.
API load testing, fuzzing, and burst runs inside Chrome. Add endpoints, generate real payloads, fire thousands of requests. Nothing leaves your browser.
Over 1,000 requests/sec from your browser
You shouldn't need a DevOps team to load test one endpoint.
Install in 30 seconds. Add your APIs. Fire. You get real payloads, configurable concurrency, burst patterns, and live metrics. All in your browser.
Everything you need to stress an API.
Local. No hidden hooks. No per-request fees.
Multi-API Definition
Define unlimited endpoints with custom methods, headers, and bodies. Switch between APIs instantly.
Dynamic Payloads
Generate unique data per request with templating tokens: {words:5}, {char:10-20}, ${VAR}
Burst Execution
Configure bursts, calls per burst, concurrency, pause intervals, and jitter for realistic load patterns.
Real-Time Metrics
Watch p50, p90, p99 latencies, success/failure rates, and error distributions live as tests run.
Environment Variables
Define base URLs and reusable variables. Switch between dev, staging, and production with one click.
Import/Export JSON
Save and share configurations. Team members can import your exact setup with one file.
Query Params
Define key-value params that become query strings for GET or form data for POST requests.
Performance Reports
Export comprehensive JSON reports with per-endpoint stats, throughput, and error analysis.
Generate Unique Data Per Request
No more static test data. Hit's templating engine generates fresh, randomized payloads for every single request - perfect for fuzzing, load testing, and finding edge cases.
-
{words:5}Generate 5 random words -
{words:3-10}Random word count between 3 and 10 -
{char:20}20 random alphanumeric characters -
{text:100}100 characters of readable text -
{string:5-50}Random length ASCII string -
${API_KEY}Environment variable substitution
{
"username": "{char:8-12}",
"email": "{char:10}@test.com",
"bio": "{words:10-25}",
"password": "{string:16}",
"metadata": {
"source": "${SOURCE}",
"session": "{char:32}"
}
}{
"username": "xK9mPqr2wL",
"email": "[email protected]",
"bio": "lorem ipsum dolor sit amet...",
"password": "Xy7$kL9#mN2@pQ4!",
"metadata": {
"source": "web_app",
"session": "a8f3b2c1d4e5f6g7h8i9j0..."
}
}Precise Control Over Load Patterns
Configure exactly how requests are sent. Test steady load, spike patterns, or gradual ramp-ups - all without writing a single line of code.
Built For Engineers Who Break Things
Load Testing
Verify your API handles expected traffic. Find bottlenecks before users do.
Fuzzing
Generate randomized payloads to discover edge cases and input validation bugs.
Concurrency Testing
Test race conditions, deadlocks, and concurrent request handling.
Performance Baseline
Establish latency baselines. Track p50, p90, p99 across releases.
See Results As They Happen
Watch your API's performance in real-time. Hit captures detailed metrics for every request and aggregates them into actionable insights.
- Total requests sent
- Success / failure counts
- Per-endpoint breakdowns
- p50, p90, p99 latency percentiles
- Min / max / avg response times
- Requests per second throughput
- Error distribution by type
- Export comprehensive JSON reports
Meet Hit Studio
One click opens a full-page command center, the same browser-native engine, with room to breathe. Now the first browser-native tool that load-tests streaming AI/LLM endpoints with real TTFT, tokens/sec, and cost metrics.
AI / LLM load testing New
The metrics k6 and Locust miss for streaming endpoints: time-to-first-token, tokens/sec, and token cost per request. Point Hit at any SSE / chat/completions API and get a real AI-UX verdict, no script, no account, no backend.
Live charts
Latency over time with p90/p99 bands, throughput, status-code mix, and a latency histogram, all updating in real time as requests fire.
Assertions & verdicts
Define pass/fail checks, status, latency budget, body contains, JSON path. Turn a load test into a green/red verdict, not just numbers.
cURL import
Paste “Copy as cURL” straight from your browser DevTools and Hit builds the request for you, method, headers, body, and all.
Load profiles
Go beyond fixed bursts: constant, ramp-up, and spike patterns to model real traffic and find the breaking point.
Collections & environments
Organize endpoints, toggle them on/off, duplicate, and switch between named environments with their own base URL and variables.
Rich exports
One run, four ways out: shareable summary, JSON report, a polished standalone HTML report, and raw CSV for your own analysis.
Why Choose Hit?
| Feature | Postman | k6 / Locust | Cloud Services | Hit by ALT.QA |
|---|---|---|---|---|
| Setup time | 5 min | 30+ min | 10+ min | 30 sec |
| High concurrency | ||||
| Dynamic payload generation | ||||
| No backend required | ||||
| No account required | ||||
| Per-request pricing | Free | $$ | Free | |
| Works offline |
From One Burst to Continuous Coverage
Hit is the free, no-friction hammer. When a burst isn't enough, the same power scales into the alt.qa platform, continuous, automated, team-wide.
Hit, start free in 30 seconds
Fire thousands of requests from your browser. Instant feedback, zero setup, data stays local.
Make any run continuous
Promote a Hit burst into a scheduled check on alt.qa. Regressions in latency or uptime get caught before users feel them, on every deploy.
Scale 100x across your team
Shared workspaces, alerting, historical p99 trends, and AI-assisted QA. The platform version of the tool you already trust.
Ready to Hammer Your APIs?
Install in 30 seconds. Start load testing in 60.
Download Free - Data Stays Local