⚭ Free Relationship Lab — Compare Two Charts Through 18 Lenses
Umbriel's free Relationship Lab compares two people through any technique you choose — and you choose one for each side, so you can put a natal chart against a draconic, or a Davison against a composite. Free, no account.
- What you'll needBoth people's birth details
- What you getA full comparison through whichever of the eighteen lenses you pick on each side, with aspects computed by the same engine as a single chart
- CostFree — no account required
Runs in your browser. Nothing to install, nothing to set up.
What it actually is
Most sites give you one synastry. The Lab gives you eighteen lenses, and lets you set them independently on each side — which is the part nothing else does.
The lenses: natal, natal with asteroids, the seven Hermetic Lots, draconic, progressed, solar arc, solar return, sidereal, the D9 and D12 divisional charts, the 5th, 7th and 9th harmonics, Davison, composite, coalescent, and the progressed and draconic composites.
Matching both sides gives a like-for-like read — two draconic charts against each other, or two ninth harmonics. Crossing them asks a stranger question: what does my everyday chart make of your soul chart?
⚠️ One combination is refused on purpose, and the page says why rather than leaving it looking like an oversight. A Davison is the chart of the two of you — identical whichever side asks — so setting it on both sides compares a chart with itself and produces a meaningless score.
How Umbriel computes it
Two charts are computed independently and then compared through whichever technique you choose on each side — and the two sides are chosen separately, so you can put one person's natal chart against the other's draconic, or a Davison against a composite. Eighteen lenses are available: natal, natal with asteroids, the seven Hermetic Lots, draconic, progressed, solar arc, solar return, sidereal, the D9 and D12 divisional charts, the 5th, 7th and 9th harmonics, Davison, composite, coalescent, and progressed and draconic composites. Aspects between the two are computed with the same engine and orbs as a single chart. The two sides are held as separate configurations rather than one shared setting, which is what makes crossing lenses possible at all — most software assumes both people are being read the same way and has nowhere to put the second choice. Where a lens is itself a two-person chart, such as the Davison or a composite, it is computed from both births and then treated as one side of the comparison, which is why setting it on both sides is refused rather than scored.
What's in your result
- Eighteen lensesNatal through to the draconic composite, listed above.
- A lens per sideSet them independently, or lock them together for a like-for-like read.
- Real aspectsComputed with the same engine and orbs as a single chart, not a simplified score.
- Fill from your libraryEither side can be loaded from a chart you have already saved.
Common questions
What is the Relationship Lab?
A two-person comparison where you choose the technique for each side separately — eighteen lenses, from natal to the draconic composite.
What does crossing two lenses mean?
Reading one person's chart in one technique against the other person's in a different one — for instance your natal against their draconic.
Why can't I put a Davison on both sides?
Because a Davison is the chart of the pair, identical from either side. Comparing it with itself scores a meaningless number, so Umbriel refuses it and explains rather than pretending.
Is this different from ordinary synastry?
Synastry is one of the eighteen. The Lab is the room that holds all of them.
Is the Relationship Lab free?
Yes, all eighteen lenses on both sides, with no account.
Go deeper
Each of these is a free tool in its own right.
Umbriel offers every system here as a set of prompts to think with, never as a statement of fact about who you are. Take what's useful, leave the rest.