Needlr
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Every page starts with a one-minute video. Then the same thing in plain words.
Getting started
What Needlr does
Needlr tells you if a change you made really moved the number you care about.
Your first 10 minutes
Sign up, see what an answer looks like, then connect your own site and measure something you shipped.
The demo project
A pretend business with sample results, so you can see what Needlr's answers look like before you connect your own site.
Your website (projects)
A project is one website you measure. Create one with your site's address, and change the address any time.
Finding your way around
Projects and the project menu, the four project tabs, the side menu, light and dark, and the Help menu.
Connect your data
Connect Google Tag Manager
Tag Manager is how Needlr shows your change to visitors and counts your KPI. You connect it once per project.
Publishing to Tag Manager
Needlr's changes reach your site only when they're published to your Tag Manager. What that means, and how to undo it.
The Needlr snippet, and why there's no flicker
What Needlr runs on your site, how each visitor gets their version, and how Needlr keeps the page from jumping.
Connect Google Analytics
Use the events Google Analytics already tracks as KPIs, and measure releases from the past year with the history it kept.
Consent and privacy on your site
Needlr follows your cookie banner: a visitor who says no isn't stored, sent or tested. And it never keeps names, emails or IP addresses.
Disconnect and remove Needlr
Take Needlr out of your Tag Manager cleanly: what it removes, what happens to running impact checks and shipped changes, and the code it asks for.
KPIs
What is a KPI?
The one number your change should move. Pick the one closest to the result your business cares about.
Create a KPI
Tell Needlr what to count: a button click, a page, a form, an event from your site, or a Google Analytics event.
Pick a button on your site
Click the button on your live site instead of typing its words, and Needlr fills in the KPI.
Google Analytics events as KPIs
Measure a release with an event Google Analytics already tracks: when that beats Needlr's own counting, how to pick one, and its limits.
KPI health and alerts
Needlr checks every hour that each KPI still counts. If one stops, you're told, and the impact checks using it wait.
A KPI's details
Point at a KPI in step 2 to see what it counts, how often it happened lately, where, which impact checks use it, and to see it on your site.
Edit or delete a KPI
Change a KPI's name or rule from a draft impact check, what a running impact check locks, and what happens to KPIs you no longer use.
Choosing a check
Which check should I use?
Four kinds of impact check, one question: is the change already live for everyone?
The new check in 3 steps
Three questions on one screen, then Start measuring. Every option, and what happens after.
Split tests
Split tests
Show your old page and your new page at the same time, and count which one works better.
The visual editor
Change your page by clicking on it: words, colors, sizes, images and more. No code.
Changes at the top of the page
Why a change visitors see right away can show a moment late, and the choice you make about it in the visual editor.
Test two pages (redirect)
Send part of your visitors from a page to a new version of it, and see which page moves your KPI.
Split test in code
Your developer wraps the new version in one line of code. Needlr decides who gets it, and counts your KPI.
Developer guide: split test in code
For the developer: how Needlr's snippet reaches the page, what impact.feature() answers, and how to ship the winner safely.
Preview version B
See your new version on your own website before anyone else does. Only your browser tab shows it, and nothing is counted.
How big and how long
How many visitors a split test needs, how long that takes, and the three settings that change it.
Why 7 days, and no peeking
Why a split test waits for its planned visitors and a full week before it calls a winner.
Before vs after
Before vs after
Measure a change that's already live for everyone, by comparing the weeks before it with the weeks after.
Measure a past release
Get a verdict on something you shipped weeks or months ago, from the history Needlr already keeps.
Releases close together
When two releases go live within two weeks of each other, a before vs after impact check can't tell which one moved the KPI.
Estimates from daily history
For older releases, Needlr counts from a summary of each day instead of every single event, so the verdict is a little more careful.
Before vs after with GA4
Measure a release with the history Google Analytics already has: up to a year back, results right away, nothing to publish.
Adoption
Adoption checks
Count how many active people use a new feature, against a target you set.
Who counts as active
Choose the people a new feature is for, so an adoption check counts the right crowd.
Targets and returning users
Set the target an adoption check aims for, read who came back, and know what each verdict means.
Reading results
The check page
One page per impact check: the needle, its band, the numbers, and when the answer comes.
Rename, start, stop or delete a check
What each button on an impact check does, and which ones can't be undone.
What the verdicts mean
Improved, Got worse, No clear effect: what each one means, and what to do next.
The range
The band around the needle: where the real difference most likely is, and why a verdict needs all of it on one side of zero.
Planned rate vs real rate
A split test is planned from a guess of your KPI's rate. Once real numbers come in, Needlr redoes the plan if the guess was far off.
Data problem: why a check is on hold
When the counting breaks, Needlr pauses the verdict instead of guessing. Here's what to fix.
Too slow to finish
When a split test can't reach its verdict at the pace visitors arrive, Needlr says so. Why it happens, and how to fix it.
Unusual traffic left out
When one source sends far more visitors or conversions than a real person could, Needlr leaves them out of the numbers and tells you.
After the verdict
Ship the winner to everyone
When version B wins a split test, show it to every visitor right away, no developer needed.
Shipped changes
Every winner shown to everyone through Needlr, and how to move each one into your site's code.
Show version A again
Take a shipped winner back: every visitor sees the original again, and the result stays as it was decided.
Export shipped changes
Download one page with every winner Needlr still applies, so a developer can move them into your site's code.
Run it again or iterate
What to do after Got worse or No clear effect, and when to run the same impact check again instead of testing a new version.
History and sharing
The release timeline
Every release you measured and what it did to its KPI, month by month, with a scorecard you can share.
Share a result
Make a link to one check's result that anyone can open, without a Needlr account, and turn it off any time.
Email and Slack alerts
Who gets told what, and when: verdicts, KPIs that stop firing and shipped-change problems, by email and in Slack.
Every email Needlr sends
The full list: results, KPI health, shipped changes, plan and usage, your account and your agents, with who gets each and when.
How long results are kept
Raw events 90 days, daily counts 13 months, and every verdict with its numbers for as long as the project exists, on every account.
Coding agents
Needlr for coding agents
Your coding agents ask Needlr whether what they ship works. They measure; you decide, and only people publish.
Connect an agent
Give a coding agent its own key: pick its projects, decide who starts its split tests, and pause or disconnect it any time.
What coding agents can and can't do
Agents measure: they create impact checks, read verdicts and record decisions. They never publish to your site, and safety rules keep their results honest.
Waiting for you
The list on the Agents page of what your coding agents need from a person: split tests to start, KPIs to create, and verdicts nobody acted on.
Agent webhooks
Needlr can post each verdict to your agent's server the moment it's ready, signed so your server knows it came from Needlr.
Agents' statistics
Split tests your coding agents run get two extra safety nets: they stop early when they clearly hurt, and a win that may be luck is marked Not confirmed.
What your agents shipped
A scorecard of your coding agents: what they asked to measure, what won, what hurt, and what waits for you. On the Agents page, and by email every Monday.
Team, account and plans
Team and roles
Invite your team as owners, editors or viewers. Viewers see everything, change nothing, and are always free.
Why live changes need a code
Anything that changes your live site asks for a code from an authenticator app. One code covers the next 20 minutes.
Sign-in, password and recovery codes
How to sign in, reset a forgotten password, and use your authenticator app and recovery codes, including when you lose your phone.
Plans and limits
One Free plan with everything and 25,000 measured visitors a month, then pay as you go if you need more. No card, and nothing is charged unless you turn it on.
Pay as you go
More than 25,000 measured visitors a month? Pay only for the ones above it, less for each as you grow, with a monthly cap you choose.
Billing and invoices
Free costs nothing and needs no card. Turn on pay as you go, change its cap, find your invoices, or ask for an annual contract, all from the Plan page.
Delete a project
Remove a website from Needlr for good: its impact checks and data, and Needlr's tags in your Tag Manager.
Trust
How Needlr decides
The method behind every verdict: a fair split, a range, a planned sample, a full week, and one call that never changes.
How often verdicts are right
We ran 192,000 simulated impact checks where the truth was known, and a test site with planted effects. Verdicts were wrong about as often as promised, and no more.
Security in plain words
What protects your site and your data: a wall around your data, a code for every live change, locked Google access, and no personal data in events.
Glossary
Words to know
Every word Needlr uses, in one plain line each.