Comparing traces
Several OTDR traces on one chart
Fibers of one cable, two wavelengths, a before and an after — the curves lie over each other, each in its own colour, sharing the cursors.
There is no cap here: as many files as you have open, that many you can overlay.
What gets compared with what
The three cases curves are actually put side by side for.
Fibers of one cable
Eight measurements on one canvas, and the odd fiber out is visible by eye. Clicking a curve makes it the working one; the rest stay where they are.
Two wavelengths
1310 and 1550 nm side by side: a bend shows up more strongly at the longer wavelength, and that difference is the only way to tell it from a splice. Wavelengths out of one .msor and out of two separate files overlay the same way.
The far-end measurement
A trace taken from the other end is drawn mirrored and brought together at the cursor. The size of the shift is printed in the legend — without it you would read a level off the curve that is not there.
There is nothing to download
This job is searched for as "otdr trace manager software" — as a program you install. There is nothing to install: the page opens by link on macOS, Windows and Linux, from a tablet and from a phone. What happens to the file you open is stated plainly in the terms of use.
What is not here yet
An overlay shows a discrepancy but does not name it: there is no line saying "fiber 7 is 0.4 dB out" until the fiber register is written. We are writing it next, and we don't want you to find that out after you have committed. Comparing and overlaying are free, and they will stay that way.
Nearby
There is not a single threshold value bundled in: what is acceptable on your site is known by your project and your customer.