Chrome Extension Pricing Models: What Top Extensions Actually Charge

TL;DR: Verified, current price points (checked July 2026, official pages): Wordtune $6.99–9.99/month, HARPA AI $12–19/month billed annually plus a $240 capped lifetime, Keywords Everywhere prepaid credits from $84/year. The pattern behind the numbers: ongoing cost ⇒ metered pricing (subscription + credits + top-ups), zero marginal cost ⇒ flat or lifetime pricing. The one trap with a documented body count: selling a capped plan as “unlimited.”

How you monetize and what you charge are different decisions. This guide is about the second one, grounded in what successful chrome extensions verifiably charge today, not in screenshot folklore.

What top extensions actually charge

Prices below were re-verified against the linked official pages in July 2026. Pricing pages change; treat the links, not this table, as authority.

Extension	Model	Verified price points
Wordtune (AI writing)	Freemium → subscription	Free: 10 rewrites/day. Advanced $6.99/mo ($4.89/mo annual). Unlimited $9.99/mo ($6.99/mo annual). 3-day trial, card required.
HARPA AI (AI automation)	Subscription + token credits	$12/mo billed annually (75 “Megatokens”/yr) · $19/mo billed annually (225/yr) · $240 lifetime with a fixed 30-Megatoken allowance + bring-your-own API keys.
Keywords Everywhere (SEO data)	Prepaid credit packs	Bronze $84/yr = 100k credits · Silver $168/yr = 400k · Gold $480/yr = 2M · Platinum $1,440/yr = 8M. 1 credit = 1 keyword lookup; credits expire after one year.

Two honesty notes. First, Monica and Sider, among the largest AI-sidebar extensions, both sell tiered subscriptions whose credit allowances gate the expensive models, but their pricing pages render prices dynamically (and Sider’s blocks automated access), so we don’t quote dollar figures we couldn’t pin to a public page; the structure is the same subscription-plus-credits pattern as HARPA. Second, none of these companies publish revenue, and neither do we for them; pricing is verifiable, “extension X makes $Y/month” claims generally are not.

The pattern: cost structure dictates the model

Sort the table by what a marginal user costs the vendor and it stops looking like a menu of choices:

• Real per-use cost (LLM calls, data APIs) → metered. Keywords Everywhere is the pure form: you prepay for exactly the thing that costs them money (API lookups). The AI assistants wrap the meter in a subscription so casual users get simplicity and the meter only surfaces for heavy use.
• Zero marginal cost (client-side utilities) → flat pricing, and lifetime becomes viable. This is where one-time purchases live.

If your extension calls a model on every use, this isn’t a taste question: unmetered flat pricing means your best users are your worst customers.

Subscription vs lifetime: the actual math

A lifetime price is a multiple of your monthly price. HARPA’s is public: $240 lifetime against $19/month Pro is ~12.6 months of revenue collected up front. The trade:

• You get: cash now, a launch-marketing lever, buyers who hate subscriptions.
• You give up: every month of value past the multiple, forever, while still paying that user’s support and (if AI) inference costs.

The break-even question is retention: if your median subscriber would have stayed longer than the multiple, lifetime pricing sells your best outcome at a discount. And for ongoing-cost products, an uncapped lifetime deal is a liability that compounds, which is why HARPA’s lifetime tier ships with a fixed token allowance and a bring-your-own-keys escape hatch rather than unlimited usage. If you sell lifetime for an AI product, copy that structure.

A defensible default: subscription as the primary offer; lifetime (capped, at 12–15× monthly) reserved for launch windows, where the urgency is real rather than manufactured.

The credits/hybrid model, done properly

For AI-cost products the converged design is three layers:

1. Subscription: predictable base revenue, and the tier a casual user understands.
2. Included credits: the monthly allowance that makes the subscription concrete, with pricier models consuming more credits per call.
3. Top-ups: prepaid packs for the heavy tail, so power users pay more by choice instead of being rate-limited into rage.

Implementation reality: credits are a server-side construct. The balance lives in your backend keyed by user ID, decremented by authenticated events; the extension only displays it. A client-side counter can be reset by a reinstall and edited by anyone who unzips the bundle. (In ExtensionStart terms: this is the metered gate preset in front, and usage/{uid} on the backend as authority; the wiring is the same webhook/entitlement architecture as in the Stripe guide.)

The fake-unlimited trap

The word “unlimited” converts, which is exactly why it keeps getting attached to plans that aren’t. The cautionary tale is Merlin: users on its feedback board documented that the “unlimited” Pro plan was in practice capped at about $100/month of equivalent usage, with accounts suspended mid-work when they crossed the invisible line, and the resulting threads use words like “misleading” in public, permanently.

The contrast is instructive: Monica’s pricing page discloses its cap in plain text: unlimited standard queries are rate-limited past 12,000 per month “to prevent abuse.” Same economics, opposite outcome, because a disclosed fair-use policy reads as honest while a discovered cap reads as a lie. The rule: if a limit exists anywhere in your stack, it exists on your pricing page.

Trials: card-up-front or not?

Wordtune’s paid plans use a 3-day trial with payment details required up front, the aggressive end of trial design. The trade is well understood from subscription-app data generally: card-up-front trials convert a far higher share of the (much smaller) group that starts them, while no-card trials maximize how many people experience the product. For extensions there’s a structural nudge toward the softer option: a free tier with visible limits (Wordtune’s own 10 rewrites/day) is a permanent no-card trial, and it keeps the fresh-install experience working, which matters for store review. If you do gate a trial, enforce “one per user” server-side; a client-side flag resets with every reinstall.

Anchoring and decoys, honestly

The standard pricing-psychology toolkit works for extensions, and none of it requires deception:

• Three tiers, middle highlighted. The top tier exists partly to make the middle one look reasonable; that’s anchoring, and it’s fine, because the top tier is real and some users genuinely need it.
• Annual discount as the decoy done right. Wordtune’s ~50%-off annual billing makes annual the obvious choice while monthly remains an honest option; the discount is real and the mechanism is transparent.
• What crosses the line: perpetual fake countdown timers, strikethrough “regular” prices that never existed, and (per the section above) “unlimited” with a secret asterisk. Beyond ethics, manufactured urgency ages terribly in Chrome Web Store reviews, which are public and permanent.

One structural advantage worth using: because extension prices live server-side, not in the reviewed bundle, price testing is a dashboard change: you can iterate toward the right number after launch instead of betting once.

Where to go from here

Price is one of three levers. The others are when the paywall appears, covered with actual evidence in paywall timing, and how you introduce paid tiers to people who knew you as free, covered in selling without burning trust.

In ExtensionStart, prices resolve by Stripe lookup key on the server and gate thresholds are remote config, so everything in this guide is tunable after launch without touching the bundle. See it working in the demo.