User pools with direct and social sign-in. 10,000 MAU free per account (Lite and Essentials). Lite is graduated — $0.0055 to 100k, $0.0046 beyond (one plan per tier). Essentials adds passkeys, managed login and more. Plus is $0.02 per MAU with no free tier. SAML/OIDC federated users are $0.015 per MAU after 50 free, on every tier.
Authentication pricing, compared
Pick a scale or set your usage. Each tool shows its cheapest plan for it, cheapest first, with the arithmetic and the vendor's pricing page. Price is one input — which one fits your situation matters as much.
Tools priced10checked since 2026-10-03
With a free plan7of 10
Side project$0 – $0a month
Growing$0 – $0a month
Scaling$0 – $12,150a month
10 of 10 tools fit this usageList prices, USD per month
Auth0Free$0/moWithin the free allowanceB2C plans. Essentials is sold in MAU blocks (500 for $35, 1,000 for $70, 2,500 for $175 … 50,000 for $3,500) — every block is $0.07 per MAU, but you pay for the whole block, so the price between blocks is higher than this linear model shows. Above 50k MAU, or on Professional ($240/mo for 1,000 MAU, rising to $3,200 for 20,000), prices are non-linear or contact-sales and are not modeled.
Auth.jsSelf-hosted (open source)$0/moWithin the free allowanceFree open-source library that runs in your own app; there is no hosted product. Hosting and database costs are yours.
Better AuthSelf-hosted (open source)$0/moWithin the free allowanceThe Better Auth framework is free and open source, running in your own app and database — hosting costs are yours. Its optional managed infrastructure (dashboard, audit logs, security detection) is priced per event and connection, not per user — Starter free, Pro $20/mo with unlimited seats — and isn't modeled.
ClerkHobby$0/moWithin the free allowanceClerk bills monthly retained users (MRU — users who come back after the day they sign up), not raw MAU, so this model is an upper bound. 50,000 MRUs included per app; graduated overage $0.02 to 100k, $0.018 to 1M, $0.015 to 10M, $0.012 beyond. Hobby gives a one-month grace period above 50k before you must upgrade. Pro is $20/mo billed annually. Business ($300/mo, $250 annual) has the same allowance and rates plus more features.
FirebaseBlaze (pay as you go)$0/moWithin the free allowanceEmail, social, anonymous and phone sign-in (Tier 1 providers). The first 50k MAU are free on both Spark and Blaze (firebase.google.com/pricing); beyond that Identity Platform's graduated rates apply — $0.0055 to 100k, $0.0046 to 1M, $0.0032 to 10M, $0.0025 beyond. SAML/OIDC users are 50 free, then $0.015 each. Phone auth SMS is billed per message on top.
KindeFree$0/moWithin the free allowanceUsers on paid subscriptions in your app aren't counted toward MAU. Plans differ in features as well as overage rate.
PropelAuthFree$0/moWithin the free allowanceGrowth Plus ($500/mo, 10,000 MAU included) has volume-discounted overage that isn't published, so it isn't modeled. SCIM is $100 per connection on Growth Plus.
SupabaseFree$0/moWithin the free allowanceThe Pro fee also covers the database and file storage (the same $25 appears in those models). Third-party auth MAUs are priced the same (100k included, then $0.00325); SSO (SAML) MAUs are 50 included, then $0.015. Free projects pause after a week of inactivity. Team ($599/mo) has the same auth allowance and rate.
WorkOSAuthKit$0/moWithin the free allowanceThe first 1M MAU are free; each additional 1M MAU costs $2,500/mo (billed per million — modeled as $0.0025 per user). Enterprise SSO and Directory Sync are $125 per connection per month (volume discounts from 16 connections), not modeled.
Read from each vendor's pricing page (oldest check 2026-10-03). The model is plan fee + usage beyond what's included × the vendor's rate; volume discounts, annual billing, taxes and regional prices are left out — see each tool's notes. Always confirm on the vendor's page before you commit.
Cost as you grow
Each tool's cheapest usable plan as the product grows.
At three scales
| Tool | Side projectmonthly active users 1k MAU | Growingmonthly active users 10k MAU | Scalingmonthly active users 250k MAU |
|---|---|---|---|
| Amazon Cognito | $0Lite | $0Lite | $1,185Lite |
| Auth0 | $0Free | $0Free | —over limits |
| Auth.js | $0Self-hosted (open source) | $0Self-hosted (open source) | $0Self-hosted (open source) |
| Better Auth | $0Self-hosted (open source) | $0Self-hosted (open source) | $0Self-hosted (open source) |
| Clerk | $0Hobby | $0Hobby | $3,725Pro |
| Firebase | $0Blaze (pay as you go) | $0Blaze (pay as you go) | $965Blaze (pay as you go) |
| Kinde | $0Free | $0Free | $3,866Scale |
| PropelAuth | $0Free | $0Free | $12,150Growth |
| Supabase | $0Free | $0Free | $513Pro |
| WorkOS | $0AuthKit | $0AuthKit | $0AuthKit |
Every plan
What each authentication plan costs, includes and caps, as modelled here.
Amazon CognitoCharged per monthly active user: the first 10,000 direct or social sign-in MAUs per account are free on Lite and Essentials, then $0.0055 per MAU on Lite ($0.0046 above 100k) or $0.015 on Essentials.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Lite | None | 10k MAU includedthen $0.0055 per MAU |
| ↳ next tier | 100k MAU includedthen $0.0046 per MAU | |
| Essentials | None | 10k MAU includedthen $0.015 per MAU |
User pools with direct and social sign-in. 10,000 MAU free per account (Lite and Essentials). Lite is graduated — $0.0055 to 100k, $0.0046 beyond (one plan per tier). Essentials adds passkeys, managed login and more. Plus is $0.02 per MAU with no free tier. SAML/OIDC federated users are $0.015 per MAU after 50 free, on every tier.
Checked 2026-10-03 · pricing page ↗ · Amazon Cognito pricing in full →Auth0Free up to 25,000 MAU; Essentials starts at $35/month for 500 MAU and is bought in fixed MAU blocks at $0.07 per user.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Free | Free | up to 25k MAU |
| Essentials | $35/mo | 500 MAU includedthen $0.07 per MAUup to 50k MAU |
B2C plans. Essentials is sold in MAU blocks (500 for $35, 1,000 for $70, 2,500 for $175 … 50,000 for $3,500) — every block is $0.07 per MAU, but you pay for the whole block, so the price between blocks is higher than this linear model shows. Above 50k MAU, or on Professional ($240/mo for 1,000 MAU, rising to $3,200 for 20,000), prices are non-linear or contact-sales and are not modeled.
Checked 2026-10-03 · pricing page ↗ · Auth0 pricing in full →Auth.jsFree open-source library that runs inside your own app; there is nothing to pay Auth.js.
| Plan | Monthly fee |
|---|---|
| Self-hosted (open source) | Free |
Free open-source library that runs in your own app; there is no hosted product. Hosting and database costs are yours.
Checked 2026-10-03 · pricing page ↗ · Auth.js pricing in full →Better AuthThe framework is free and open source; optional managed infrastructure is free on Starter or $20/month on Pro, plus usage charges for audit logs, security detections, email and SMS.
| Plan | Monthly fee |
|---|---|
| Self-hosted (open source) | Free |
The Better Auth framework is free and open source, running in your own app and database — hosting costs are yours. Its optional managed infrastructure (dashboard, audit logs, security detection) is priced per event and connection, not per user — Starter free, Pro $20/mo with unlimited seats — and isn't modeled.
Checked 2026-10-03 · pricing page ↗ · Better Auth pricing in full →ClerkFree up to 50,000 monthly retained users per app; Pro is $25/month ($20 billed annually) with 50,000 included, then from $0.02 per retained user.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Hobby | Free | up to 50k MAU |
| Pro | $25/mo | 50k MAU includedthen $0.02 per MAU |
| ↳ next tier | 100k MAU includedthen $0.018 per MAU | |
| ↳ next tier | 1M MAU includedthen $0.015 per MAU | |
| ↳ next tier | 10M MAU includedthen $0.012 per MAU |
Clerk bills monthly retained users (MRU — users who come back after the day they sign up), not raw MAU, so this model is an upper bound. 50,000 MRUs included per app; graduated overage $0.02 to 100k, $0.018 to 1M, $0.015 to 10M, $0.012 beyond. Hobby gives a one-month grace period above 50k before you must upgrade. Pro is $20/mo billed annually. Business ($300/mo, $250 annual) has the same allowance and rates plus more features.
Checked 2026-10-03 · pricing page ↗ · Clerk pricing in full →FirebaseThe first 50,000 monthly active users are free, then Identity Platform's graduated per-MAU rates apply, from $0.0055 down to $0.0025.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Blaze (pay as you go) | None | 50k MAU includedthen $0.0055 per MAU |
| ↳ next tier | 100k MAU includedthen $0.0046 per MAU | |
| ↳ next tier | 1M MAU includedthen $0.0032 per MAU | |
| ↳ next tier | 10M MAU includedthen $0.0025 per MAU |
Email, social, anonymous and phone sign-in (Tier 1 providers). The first 50k MAU are free on both Spark and Blaze (firebase.google.com/pricing); beyond that Identity Platform's graduated rates apply — $0.0055 to 100k, $0.0046 to 1M, $0.0032 to 10M, $0.0025 beyond. SAML/OIDC users are 50 free, then $0.015 each. Phone auth SMS is billed per message on top.
Checked 2026-10-03 · pricing page ↗ · Firebase pricing in full →KindeFree up to 10,500 MAU; paid plans from $25/month include 10,500 MAU, then $0.0151–$0.0175 per extra MAU, and users on paid subscriptions billed through Kinde don't count.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Free | Free | up to 10.5k MAU |
| Pro | $25/mo | 10.5k MAU includedthen $0.0175 per MAU |
| Plus | $75/mo | 10.5k MAU includedthen $0.0163 per MAU |
| Scale | $250/mo | 10.5k MAU includedthen $0.0151 per MAU |
Users on paid subscriptions in your app aren't counted toward MAU. Plans differ in features as well as overage rate.
Checked 2026-10-03 · pricing page ↗ · Kinde pricing in full →PropelAuthFree up to 10,000 MAU; Growth is $150/month with 10,000 MAU included, then $0.05 per extra user.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Free | Free | up to 10k MAU |
| Growth | $150/mo | 10k MAU includedthen $0.05 per MAU |
Growth Plus ($500/mo, 10,000 MAU included) has volume-discounted overage that isn't published, so it isn't modeled. SCIM is $100 per connection on Growth Plus.
Checked 2026-10-03 · pricing page ↗ · PropelAuth pricing in full →SupabaseFree up to 50,000 MAU; Pro is from $25/month (shared with the database and storage) with 100,000 MAU included, then $0.00325 per MAU.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| Free | Free | up to 50k MAU |
| Pro | $25/mo | 100k MAU includedthen $0.00325 per MAU |
The Pro fee also covers the database and file storage (the same $25 appears in those models). Third-party auth MAUs are priced the same (100k included, then $0.00325); SSO (SAML) MAUs are 50 included, then $0.015. Free projects pause after a week of inactivity. Team ($599/mo) has the same auth allowance and rate.
Checked 2026-10-03 · pricing page ↗ · Supabase pricing in full →WorkOSAuthKit is free up to 1 million monthly active users, then $2,500/month per additional million; enterprise SSO and Directory Sync are $125 per connection per month.
| Plan | Monthly fee | Monthly active users |
|---|---|---|
| AuthKit | None | 1M MAU includedthen $0.0025 per MAU |
The first 1M MAU are free; each additional 1M MAU costs $2,500/mo (billed per million — modeled as $0.0025 per user). Enterprise SSO and Directory Sync are $125 per connection per month (volume discounts from 16 connections), not modeled.
Checked 2026-10-03 · pricing page ↗ · WorkOS pricing in full →