Track 11+ providers in one dashboard

Stop surprise API bills
in their tracks

One dashboard for all your API costs. Auto-disable keys before you hit budget limits. Get alerted at 80%, disabled at 100%. Your keys never leave your browser. Sign up free.

Get started free See all features
Free account, no credit card Privacy-first Open source

Supported APIs

OpenAI, Anthropic, Cohere, Replicate + 8 more

Auto-pause at limits, reverts when period resets. Add any OpenAI-compatible endpoint as a custom provider.

OpenAI
GPT + Billing
Anthropic
Claude
Google Gemini
API Quota
OpenRouter
Multi-model
Stripe
Payments
Vercel
Hosting
GitHub
Copilot
Perplexity
Search API
ElevenLabs
Voice quota
Resend
Email volume
Cohere
Text AI
Custom
OpenAI compat.

Features

Everything you need to stay in control

From real-time spend monitoring to budget forecasting — built for developers who care about their bill.

Real-time spend monitoring
Live polling every 60 seconds. Per-key daily, weekly, and monthly breakdowns with today vs. yesterday delta chips.
Free
Auto-disable on budget breach
Set daily, weekly, or monthly spend limits per key. Keys are automatically disabled when a limit is breached — and re-enabled when the period resets.
Free
Threshold alerts
Browser push notifications at 80% of your limit. Auto key-disable at 100%. Configurable: disable, notify, log, or all three.
Free
Anomaly detection
Flags any key where today's spend exceeds 2.5× its 7-day average. Spike badges appear in the overview before small problems become big bills.
Pro
Budget forecasting
Linear projection of end-of-month spend. Warning when forecast exceeds 1.5× current spend. Shows daily average, projected total, and days remaining.
Pro
Folder organisation
Color-coded folders to group keys by project, client, or environment. Each shows total spend and key count. Nothing gets lost.
Pro
14-day spend history
Stacked daily spend charts, per-provider doughnut charts, and per-key sparklines. Up to 30 days of history in your browser — no server.
Free
Bulk actions & CSV export
Select multiple keys and apply limits in one click. Export full spend history as JSON backup or CSV for invoicing.
Pro
100% private by design
Your API keys live only in your browser. All calls go directly from your browser to the provider — no proxy, no intermediary, no server.
Free

How it works

Simple as opening a file

No installation needed. Sign up, add your keys, and you're live in under a minute.

1
Create your account
Sign up at app.apimonitor.ai with your email. Takes 30 seconds — no credit card required for the Free plan.
2
Add your API keys
Paste in keys for each provider. They're stored in your browser — they never leave your machine.
3
Set your limits
Configure daily, weekly, or monthly spend limits per key. Set the threshold at which you want to be notified (default: 80%).
4
Monitor & relax
The dashboard polls every 60 seconds. Leave it running in a tab — it works offline after first load.
100% client-side JavaScript
Keys never touch our servers
Works offline after first load
Synced across your devices
Chrome, Firefox, Safari, Edge
PWA-ready, add to home screen

Use cases

Built for everyone with an API bill

💻
Prevent runaway Discord bot costs
Set a daily limit on your bot's key. It auto-disables before a runaway loop turns a $5 experiment into a $500 surprise.
🧪
Monitor staging environment limits
Separate keys for dev, staging, and prod — grouped by folder. Catch staging budget creep before it masks production spend.
🗂️
Track multiple keys across projects
One dashboard for every client project. See exactly what each client is costing and export a CSV for invoicing.
🚀
AI startup multi-environment ops
Monitor dev/staging/prod with separate API keys per environment. Get alerted when any environment shows anomalous spending.
🏢
Enterprise multi-team visibility
Centralize visibility across dozens of keys. Use bulk actions to disable groups instantly and forecast monthly burn.
📊
Cost audit & finance reporting
Export full spend history to CSV, review anomaly detections, and produce period-over-period comparisons for finance teams.

Pricing

Free forever for personal use

Start free. Upgrade to Pro when your team needs advanced features.

Monthly
Annual
Save 22%
Free
$0
/mo
Everything you need to monitor personal API keys and stay under budget.
Start free — no card needed
Up to 3 API keys
Real-time spend monitoring
Spend limits & auto-disable
80% / 100% threshold alerts
7-day spend history
All 11+ providers
Anomaly detection
Budget forecasting
Projects & folders
Most popular
Pro
$9
/mo
Billed monthly. All the tools for teams, agencies, and power users.
Upgrade to Pro
Unlimited API keys
Everything in Free
Anomaly detection (2.5× spike)
Budget forecasting & projections
Projects & folders
30-day history per key
Bulk actions & CSV export
Priority support

Free forever for personal use. Pro features for teams. No credit card required to start.

FAQ

Common questions

Yes. API Monitor is privacy-first — your API keys are stored only in your browser's local storage. All API calls go directly from your browser to the provider endpoint. There is no proxy and no intermediary. Your account is secured by Supabase Auth, and you can verify every network request by opening DevTools.
The Free tier is genuinely free — no credit card, no time limit, no catch. You get real-time monitoring, spend limits, auto-disable, and threshold alerts for up to 3 keys. Pro ($9/mo or $7/mo annual) adds unlimited keys, anomaly detection, budget forecasting, folder organisation, 30-day history, and CSV export.
When a key hits its spend limit, API Monitor can automatically disable it through the provider's API (where supported). The key is re-enabled automatically when the billing period resets. You receive a push notification at 80% of your limit and another when a key is disabled. Configurable: disable only, notify only, log only, or all three.
Yes — after the first load, the file is cached and the app opens offline. Live polling of your API provider balances requires an internet connection, but all historical data, charts, and settings are always accessible locally.
Yes. API Monitor is PWA-ready. On iOS, tap the Share button in Safari and choose "Add to Home Screen". On Android, tap the browser menu and choose "Add to Home Screen" or "Install App". Once added, it launches in full-screen mode with the custom icon and opens offline.
Yes. API Monitor supports any OpenAI-compatible endpoint as a custom provider. If your provider exposes a compatible usage or billing API, you can add it as a custom entry and track it alongside the built-in providers.

What developers say

Built for people who build

★★★★★
“I got hit with a $340 OpenAI bill because a test script ran overnight. API Monitor would have killed the key at my limit. This is exactly what I needed.”
JR
Jake R.
Full-stack developer
★★★★★
“We use 6 different AI APIs across projects. Having one dashboard with budget limits per key has saved us from at least two billing surprises already.”
SM
Sofia M.
AI product lead
★★★★★
“The 80% alert is a game-changer. I get notified before the limit hits, not after. Clean UI, no bloat — it just works.”
TK
Thomas K.
Independent developer

Never wake up to a surprise API bill again

One file. All your providers. Full control. Free forever for personal use.

Get started free Star on GitHub
Free forever, no credit card
Privacy-first
Open source
Free forever for personal use