RulerFlow – Pixel-Perfect Chrome Page Ruler
RulerFlow – Pixel-Perfect Chrome Page Ruler is free on the Chrome Web Store.
Install the official NIUBIAPP extension directly from Google. Every feature is included.
PIXEL-PERFECT PAGE RULER
Measure any part of a webpage without leaving the page.
RulerFlow draws a precise on-page ruler with live width, height, start, and end coordinates. Drag, fine-tune, and copy the result.
Every feature is free. No account, ads, analytics, host permissions, remote code, or paid unlock. Optional support is available through Creem.
Turn a visual guess into exact pixels
Activate RulerFlow from the toolbar, drag across the area you want to measure, and read the dimensions directly on the page.
Drag to measure
Draw a rectangle over any visible part of the current webpage.
See live metrics
Width, height, and both coordinate pairs update while the pointer moves.
Copy the result
Copy the complete measurement for a design note, issue, or handoff.
LIVE COORDINATES
Width, height, start, and end—updated as you move.
RulerFlow keeps the numbers attached to the measurement instead of sending you to a separate panel.
- Width and height show the rectangle size in pixels.
- Start and end coordinates keep the selection easy to reproduce.
- Drag in any direction and the measurement remains readable.
- Copy once to capture the complete result.
KEYBOARD PRECISION
Fine-tune the selection one pixel at a time.
After drawing the rectangle, use the keyboard when the pointer alone is not precise enough.
- Arrow keys adjust the active edge by 1 pixel.
- Shift + Arrow moves it by 10 pixels.
- Copy sends width, height, start, and end to the clipboard.
- Escape clears the selection, then closes the ruler.
A grid when alignment matters
The optional 50-pixel grid makes page rhythm, spacing, and alignment easier to judge while you measure.
50-pixel reference
Use consistent visual intervals without opening developer tools or changing the page layout.
Temporary overlay
The ruler appears only when you activate it and disappears when you turn it off.
Page stays yours
RulerFlow measures the visible page without editing the website or saving page content.
PRIVATE BY DEFAULT
Page access begins only when you click.
RulerFlow uses Chrome’s temporary active-tab access to place the ruler on the page you choose. It does not request permanent access to every website.
- Two permissions: activeTab and scripting.
- No host permissions and no background browsing-history access.
- No analytics, ads, uploads, accounts, or remote code.
- English and Simplified Chinese interfaces with the same local measurement behavior.
Read the site-wide Privacy Policy or email [email protected] with a privacy question.
Free to use. Optional to support.
RulerFlow does not sell access to measurement features. Optional support helps NIUBIAPP keep improving independent browser tools.
Support is voluntary and does not unlock, remove, or change any feature.
RulerFlow FAQ
How do I start measuring?
Click the RulerFlow toolbar icon on the tab you want to measure, then drag across the page.
Does it run on every website?
No. Chrome grants temporary access only after you activate RulerFlow on the current tab.
Does it upload page content?
No. Measurement happens inside the active webpage and page content is not uploaded by the extension.
Is the support payment required?
No. Support is optional. The ruler, grid, keyboard controls, and copy action remain free.
Measure the page, not the guesswork.
RulerFlow is free on the Chrome Web Store. Every measurement feature is included—install it directly from Google, with optional support that never unlocks or changes features.