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How Lease X-Ray works

The AI reads and explains, but the law comes from a curated, cited rule library. If the model cites a law we don't have, the system rejects it.

The pipeline

  1. 1
    Extract

    Read the PDF's text and the exact position of every word on the page.

  2. 2
    Segment

    Split the lease into clauses using its numbering and headings.

  3. 3a
    Rule checks

    Deterministic tests: deposit over the cap? late fee too high? “waive”, “change the locks”…

  4. 3b
    AI review

    The model classifies each clause, but may only cite rule IDs from our library.

  5. 4
    Validate

    Unknown rule IDs are rejected and downgraded to “needs review”. Rule checks win ties.

  6. 5
    What's missing

    Look for required protections and disclosures that appear nowhere in the lease.

  7. 6
    Highlight

    Find each clause's text on the page and draw colored boxes over it.

  8. 7
    Report

    Lease Health Score, plain-English report and a negotiation letter.

Grounding

The AI can only cite laws from our library. Every rule has an ID, a plain-English summary, and a citation. When the model returns a rule ID that isn't in the library, we drop it and mark the clause “needs review.” A clause can only be marked “likely illegal” if a library rule backs it.

51
jurisdictions (50 states + DC)
152
state-specific rules
6
federal + model-law rules
11
one-sided patterns

Coverage levels. NJ and NY have in-depth, hand-built libraries (deposit accounts, anti-eviction, roommate and sublet rights, required disclosures and more). Every other state gets core statewide rules generated from a cited table (deposit caps, deposit return deadlines, entry notice and late-fee limits where the state has them), plus federal Fair Housing Act rules and three nationwide principles from the Uniform Residential Landlord and Tenant Act (habitability, no lockouts, no retaliation), which are labeled “model law” so tenants know to confirm their state's own statute.

Browse the full rule library →

Scoring

The Lease Health Score is a simple, transparent formula:

100 − (18 × likely illegal) − (6 × one-sided) − (5 × missing protections), clamped to 0–100

  • 80–100 Fair · 50–79 Needs changes · 0–49 Serious problems
  • Each likely-illegal clause costs 18 points, each one-sided clause 6, each missing protection 5.

Evaluation

We wrote three test leases for the in-depth states (two New Jersey, one New York) with 46 planted problems, turned them into PDFs, and ran them through the full pipeline: PDF text extraction, segmentation, checks and scoring. The sample lease was used during development. The two test leases were written afterward, and no rules were changed after running them. Misses are shown, not hidden.

Rule checks only (no AI)
Caught 41/46 planted issues
41/46 at the expected severity · 0 false positives
nj-sample-lease.pdf · NJ
  • 2-month security deposit
  • Habitability / repairs waiver
  • Lockout clause
  • Landlord-only attorney fees
  • $150 late fee on day 1
  • Jury trial waiver
  • Entry at any time
  • Auto-renewal, 90-day notice
  • Missing: NJ-DEP-ACCOUNT
  • Missing: NJ-ATTY-RECIP
nj-test-lease-2.pdf · NJ
  • Deposit over 1.5 months
  • 45-day deposit return
  • Repair waiver
  • No-cause termination
  • Blanket liability waiver
  • Mid-lease rent increase
  • Pay all remaining rent to leave early
  • Mandatory arbitration
  • Missing: NJ-FLOOD-DISC
ny-test-lease-3.pdf · NY
  • Deposit over one month
  • Move-in fee
  • $75 late fee
  • Roommate restriction
  • Sublet ban (20 units)
  • Negligence waiver
  • No duty to re-rent
  • Auto-renewal
  • Owner-only attorney fees
  • Jury waiver
  • Missing: NY-DEP-TRUST
  • Missing: NY-ATTY-RECIP
  • Missing: NY-SPRINKLER
ca-test-lease-4.pdf · CA
  • 2-month deposit
  • Adults-only occupancy
  • Entry at any time
  • Repair waiver
  • Late fee after 2 days
  • Mandatory arbitration
  • Missing: US-LEAD-DISC
tx-test-lease-5.pdf · TX
  • 45-day deposit refund
  • Late fee before 2 full days
  • Electricity shutoff
  • Ban on reporting to code inspector
  • No assistance-animal exception
  • Entry at any time
  • Jury waiver

Small, self-written test set: treat these as a sanity check, not a benchmark. “Caught” means the clause was flagged; “expected severity” means it got the right label.

Privacy

  • Your PDF is read in your browser. Only the extracted text is sent for analysis.
  • “Redact names & addresses” (on by default) replaces names, street addresses, emails and phone numbers with placeholders before anything leaves your device.
  • Leases are processed in memory and never stored or logged. There are no accounts.
  • If AI review is enabled, clause text is sent to the model provider for that request only.

Limitations

  • Residential leases in all 50 states and DC. New Jersey and New York have in-depth coverage; other states have core coverage (see above).
  • The 50-state table was compiled from two independent secondary sources and cross-checked; where they disagreed we used the more recent law. It still needs attorney review.
  • The rule library is not exhaustive. A clause marked “standard” means none of our rules flagged it, not that it's guaranteed to be fair or legal.
  • Local ordinances (like rent control or rent stabilization, city-specific notice rules, or municipal registration) aren't covered. If you enter your city, we remind you to check local rules.
  • Some protections depend on facts we can't see, such as building size, owner occupancy, or the tenant's age. We flag these as “needs review.”
  • Scanned image PDFs aren't supported yet; paste the text instead.
  • The rule library is pending attorney review. Citations are marked until verified against the official text.
  • Explanations appear in 10 languages when AI review is on; without it, rule explanations are in English. Negotiation letters are always in English, for the landlord.
  • Lease X-Ray does not replace a lawyer. For help, find free legal aid at LawHelp.org.