The Calibre Insider’s Guide
Everything we know about Calibre in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.
Calibre
The Insider’s Guide
Web performance monitoring with RUM, CrUX data and synthetic tests
Every plan, grade, refund rule and rival among technical SEO tools, read from Calibre’s own pages.
Made by Calibre Analytics · checked Oct 23, 2026 · toolgpa.com
Contents
- 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
- 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
- 03What it doesIts main features, where it runs, what it works with and who makes it
- 04Where it standsIts grades against its category, and whether to keep it or make your own
- 05The alternativesThe tools it is most often weighed against, side by side
- 06Quick answersThe questions people ask about it, each answered in a line or two
- 07About ToolGPAWho made this guide, what else is on the site, and how to cite it
ToolGPA put this guide together from Calibre’s own pages, its app-store listings and our grades. Every fact in it is on Calibre’s page too, where it is kept up to date. Checked Oct 23, 2026.
Part 01 · Overview
Welcome
What it is, who it suits, its grades and the ten things to know first
2.2
GPA, above 20 of the 83 other technical SEO tools we grade
Calibre is a web performance monitoring platform that combines real user monitoring, Google's Chrome UX Report data and scheduled synthetic page speed tests. It ranks a team's sites by speed, shows which pages pass Core Web Vitals, and breaks down the effect of third-party scripts and slow interactions. Plans are priced by real user sessions, synthetic tests and seats.
To get you started, here are 9 things to know about Calibre, taken from its own pages and our grades.
You add sites, test profiles and real user tracking, and watch the session and test allowances so monitoring doesn't pause.
- 1
Best for speed monitoring across many sites
Calibre combines real user monitoring, Google's CrUX data and scheduled lab tests, ranks every site you watch by speed, and allows unlimited sites from Starter.
- 2
Paid plans start at $75 a month
As its pricing page puts it: $75 per month, billed monthly or $900 a year.
- 3
You can try it first
15-day free trial, no credit card required
- 4
It runs on Web
Web.
- 5
Real user monitoring
Collects Core Web Vitals from real browser sessions, with adjustable sampling and attribution of the page elements behind slow interactions.
- 6
Chrome UX Report monitoring
Tracks Google's CrUX field data for every monitored site and shows which pages pass the Core Web Vitals assessment.
- 7
Synthetic page speed tests
Scheduled and on-demand lab tests for each URL and test profile, with synthetic snapshots kept for the life of the account.
- 8
A 2.2 GPA, above 20 of 83
That is against the other technical SEO tools we grade, on value, the free plan, features, ease of use and platforms.
- 9
Keep it
Nothing Calibre does is plain enough to make in a weekend. The 2 things listed below take a company.
Calibre at a glance
- Pricing
- Free trial, from $75 per month, billed monthly or $900 a year
- Free plan
- No
- Free trial
- 15-day free trial, no credit card required
- Runs on
- Web
- Made by
- Calibre Analytics, since 2017
- Category
- Technical SEO & Site Audits
- Our grade
- 2.2 GPA, fair
The report card
Best for speed monitoring across many sites
Calibre combines real user monitoring, Google's CrUX data and scheduled lab tests, ranks every site you watch by speed, and allows unlimited sites from Starter. There's no free plan, monitoring stops when the monthly test allowance runs out, yearly billing saves nothing, and cancelling deletes all your data at once.
| Subject | Grade | Comment |
|---|---|---|
| Value for money | C | Starter is $75 a month, or $900 a year, for 5,000 real user sessions, 5,000 lab tests and 3 seats, at this category's dearer quarter. Team is $150 and Company $1,500 a month paid yearly. |
| Free plan and trial | C | No free plan, but the 15-day trial needs no card. |
| Features | C | Real user Core Web Vitals with interaction attribution, CrUX for every site, scheduled lab tests, third-party script impact, a CLI, Node.js API and GitHub pull request checks. It does speed monitoring fully, but that's a smaller job, and tests stop at the allowance. |
| Ease of use | C | No rating on record. You add sites, test profiles and real user tracking, and watch the session and test allowances so monitoring doesn't pause. |
| Platforms and integrations | B | Web, with a command-line client, Node.js API, webhooks, GitHub, Slack, Zapier, Netlify and Render. No desktop or phone app. |
An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.
Who Calibre is for
- Fits if you watch lots of sites, since Starter allows unlimited sites
- Works for developers who want speed checks on each GitHub pull request
Who it is not for
- Watch out: monitoring stops when the monthly test allowance runs out, unless you buy packs at $60 per 5,000
- Tight if you get real traffic, as Starter's real user tracking pauses at 5,000 sessions a month
- Pricey if your team grows, at $15 a month for each seat past those included
- Watch out: cancelling deletes all of an account's data immediately and permanently
- Pricey if you pay yearly expecting a discount, as $900 is the same as 12 monthly payments
Good to know
Good for
- SEOs tracking the Core Web Vitals data Google uses
- Agencies monitoring and benchmarking many client sites
- Product teams adding speed checks to pull requests and deploys
Worth knowing
- There is no free plan, and monitoring stops when the monthly test allowance runs out unless you add test packs at $60 per 5,000.
- Starter's real user tracking pauses at 5,000 sessions a month; Team includes 10,000 and then charges $75 per 100,000.
- Seats beyond those included cost $15 a month each, and paying yearly costs the same as 12 monthly payments.
- Cancelling deletes all of an account's data immediately and permanently.
Part 02 · Pricing
What it costs
Every plan, the free plan, ways to pay less and how prices have moved
$75
A month to start
Calibre is a paid product with a free trial, starting at $75 per month, billed monthly or $900 a year.
Starter
$75
per month, billed monthly or $900 a year
5,000 real user sessions and 5,000 synthetic tests a month, CrUX data, 3 seats, unlimited sites, 1 team and 90 days of RUM data.
Team
$150
per month, billed monthly or $1,800 a year
10,000 real user sessions, 15,000 synthetic tests, 10 seats, unlimited teams, SAML single sign-on and 1 year of RUM data.
Company
$1,500
per month, paid yearly
1 million real user sessions, 50,000 tests, 50 seats, a security audit log, invoice payment, priority support and 2 years of RUM data.
Trying it first
15-day free trial, no credit card required
Read from calibreapp.com on Oct 23, 2026.
Part 03 · Features
What it does
Its main features, where it runs, what it works with and who makes it
1
Place it runs: Web
Web performance monitoring with RUM, CrUX data and synthetic tests. Here is what it does, as its own site describes it, and what it covers: public API, page speed.
It does speed monitoring fully, but that's a smaller job, and tests stop at the allowance.
- Real user monitoring
- Collects Core Web Vitals from real browser sessions, with adjustable sampling and attribution of the page elements behind slow interactions.
- Chrome UX Report monitoring
- Tracks Google's CrUX field data for every monitored site and shows which pages pass the Core Web Vitals assessment.
- Synthetic page speed tests
- Scheduled and on-demand lab tests for each URL and test profile, with synthetic snapshots kept for the life of the account.
- Third-party impact
- Breaks down how external scripts and other third-party resources affect each page's load and responsiveness.
- Developer tooling
- A command-line client, Node.js API, webhooks, GitHub pull request checks and CI/CD hooks to test before and after deploys.
- Sites ranked by speed
- An overview that ranks every monitored site by performance, with alerts sent to Slack and deploy markers from Netlify.
Where it runs
- Web
What it works with
- GitHub
- Slack
- Zapier
- Netlify
- Render
Calibre is made by Calibre Analytics, and has been around since 2017.
Part 04 · Standing
Where it stands
Its grades against its category, and whether to keep it or make your own
20/83
Other technical SEO tools it is graded above
Calibre's GPA of 2.2 is higher than 20 of the 83 other technical SEO tools we grade, and level with 20.
It stands best on platforms and integrations (B, above 27 of 83) and worst on ease of use (C, above 7).
Its paid plans start at $75 a month, against a middle price of $22.41 for the category: 40 of the 52 others that charge start lower.
On features, ease of use and platforms it scores 2.3 out of 4. 6 tools score higher and cost less.
Each grade against the category
Every bar is all 84 technical SEO tools we grade, cut by the letter each got. Calibre’s own letter is outlined.
- CValue for moneyAbove 9 of 83
- CFree plan and trialAbove 18 of 83
- CFeaturesAbove 10 of 83
- CEase of useAbove 7 of 83
- BPlatforms and integrationsAbove 27 of 83
Price against what you get
Each dot is one of 73 technical SEO tools. Further left costs less; higher up scores better on features, ease of use and platforms. Calibre is the marked dot.
What paid plans start at, a month (each step along is roughly double) →
Keep it, or make your own?
Whether this is something you could build for yourself with an AI app builder, and what you would give up.
Keep it
Nothing Calibre does is plain enough to make in a weekend. The 2 things listed below take a company.
That makes this kind of software worth paying for, not this one in particular: 43 of the 83 other technical SEO tools grade higher. It costs $900 a year.
What you could not
- Speed tests run from real browsers on a schedule.
- It plugs into other products, GitHub, Slack and Zapier among them, and has an API.
What this rests on. Calibre’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
Part 05 · Alternatives
The alternatives
The tools it is most often weighed against, side by side
DebugBear, SpeedCurve, GTmetrix, WebPageTest and Treo
The 5 tools Calibre is most often weighed against, with where each one differs from it.
- 2.2GPA
DebugBear
Free trial · from $99/mo
Page speed and Core Web Vitals monitoring with lab tests and RUM.
- DebugBear also covers dashboards.
- 2.2GPA
SpeedCurve
Free trial · from $90/mo
Web performance monitoring with RUM, synthetic tests and budgets.
- SpeedCurve also covers dashboards.
- 2.8GPA
GTmetrix
Free plan · from $4.99/mo
Page speed testing with Lighthouse reports, monitoring and an API.
- GTmetrix has a free plan. Calibre does not, though it has a free trial.
- 2.6GPA
WebPageTest
Free plan · from $180/yr
Page speed tests from real browsers in locations around the world.
- WebPageTest has a free plan. Calibre does not, though it has a free trial.
- WebPageTest also covers dashboards.
- 2.2GPA
Treo
Free plan · from $75/mo
Core Web Vitals dashboard built on CrUX data and Lighthouse runs.
- Treo has a free plan. Calibre does not, though it has a free trial.
Part 06 · Questions
Quick answers
The questions people ask about it, each answered in a line or two
13
Questions, each answered in a line or two
The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.
Is Calibre free?
No, Calibre is a paid product, but you can try it first. 15-day free trial, no credit card required.
How much does Calibre cost?
Calibre lists 3 plans. Starter: $75 per month, billed monthly or $900 a year.
What platforms does Calibre work on?
Calibre is available on Web.
Does Calibre have an Android app?
No Android app was listed when its pages were read on Oct 23, 2026. Calibre is listed for Web.
Does Calibre have an iPhone app?
No iPhone app was listed when its pages were read on Oct 23, 2026. Calibre is listed for Web.
Is Calibre open source?
Calibre is not described as open source on its own site, as read on Oct 23, 2026.
Does Calibre have an API?
Yes. Calibre offers a public API, according to its own site.
What does Calibre integrate with?
Calibre's listing names GitHub, Slack, Zapier, Netlify and Render. A listing names up to eight integrations, so it may connect to more.
Who makes Calibre?
Calibre is made by Calibre Analytics. It dates from 2017.
What are the alternatives to Calibre?
The closest alternatives to Calibre in our directory are DebugBear, SpeedCurve, GTmetrix, WebPageTest and Treo.
How does Calibre compare with other technical SEO tools?
Calibre's GPA of 2.2 is higher than 20 of the 83 other technical SEO tools we grade, and level with 20.
Is Calibre good value for money?
ToolGPA grades Calibre C for value for money. Its paid plans start at $75 a month, against a middle price of $22.41 for the category: 40 of the 52 others that charge start lower.
Could I make my own version of Calibre?
Nothing Calibre does is plain enough to make in a weekend. The 2 things listed below take a company.
Where this guide comes from
The prices, plans, platforms and features were read from Calibre’s own pages on Oct 23, 2026, and the grades were given on Oct 23, 2026. Graded from this listing, whose facts were read from Calibre's own pages on 23 October 2026. Not based on using the product, and shorter than our full reviews.
Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by Calibre Analytics. Prices change, so check calibreapp.com before you buy.
Part 07 · About
About ToolGPA
Who made this guide, what else is on the site, and how to cite it
3,189
Tools graded, in 94 categories
ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.
Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.
3,189
tools graded
94
categories
426
price changes on record
579
apps priced in 12 countries
What else is on toolgpa.com
- Calibre, kept up to dateEverything in this guide, with prices and grades as they are todaytoolgpa.com/tools/calibre
- How grades are givenThe rules behind every letter and every GPAtoolgpa.com/grades
- Value chartsWhat each tool costs against what it scores, for every categorytoolgpa.com/charts
- CompareAny two tools side by side, plan by plantoolgpa.com/compare
- Price changesEvery price rise and cut on record, each with its sourcetoolgpa.com/price-changes
- Prices by countryWhat apps cost on the App Store in 12 countriestoolgpa.com/prices-by-country
- Pay lessEvery public discount: yearly billing, students, nonprofitstoolgpa.com/save
- Keep or makeWhich tools are worth paying for, and which you could build yourselftoolgpa.com/keep-or-make
Scan for the live page
Prices and grades as they are today
Quoting this guide?
Please name ToolGPA and link to the live page, so readers can check the figures for themselves:
ToolGPA, "Calibre: The Insider's Guide", checked Oct 23, 2026. https://toolgpa.com/tools/calibre
Know someone choosing between technical SEO tools?
Send them this guide: toolgpa.com/tools/calibre/guide
ToolGPA elsewhere: youtube.com/@toolgpa
See our other guides
The best-graded technical SEO tools after Calibre, each with an Insider's Guide of its own.
- Technical SEO & Site Audits Insider's GuideEvery one of the 84 technical SEO tools we grade, compared
- Lighthouse Insider's GuideGoogle's open-source audit of page speed, accessibility and SEO3.2 GPA
- PageSpeed Insights Insider's GuideFree Google speed test with real-user Core Web Vitals and Lighthouse3.2 GPA
- Yellow Lab Tools Insider's GuideFree open-source audit of a page's speed and front-end code3.2 GPA
Choosing software? Every tool graded, every price dated.
Compare tools at toolgpa.com ›Everything in this guide is ToolGPA’s own summary of what Calibre’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Calibre is a trademark of its owner, and this guide is not made, paid for or approved by Calibre Analytics. Prices and plans change: check calibreapp.com before you buy.