Boleto Verifier
Decodes a boleto's digitable line or PDF and checks its verification digits.
The digitable line you paste, or the boleto PDF you select/drop, never leave your browser — reading the file, decoding, and verification-digit validation happen entirely on your own device, with no network call.
What the digitable line and the barcode are
Every boleto carries the same information in two forms: the barcode (44 digits, read by an optical scanner at the register) and the digitable line (the longer, 47- or 48-digit number printed above or below the barcode, typeable by hand when the barcode can't be scanned). Both encode the bank/issuer, the amount, and — on a bank slip — the due date; the digitable line just adds three extra check digits, one per block, so a cashier can type it in part by part without losing error detection.
Why there's a check digit
A check digit (DV) is calculated mathematically from the document's other digits (module 10 or module 11, public algorithms defined by FEBRABAN) and detects typos or a one-off tamper — changing a single digit almost anywhere else in the number makes the check digit stop matching. It's the same principle behind a CPF/CNPJ or credit card check digit, applied to the boleto.
The tampered-boleto scam
The most common scam doesn't touch the amount or the due date — it swaps the beneficiary's data (the bank code and the free field, which identifies the destination account) while keeping the document's visual appearance identical to the original, even in a PDF intercepted by email. Since the check digit is computed from the real digits, a boleto tampered this way almost always ends up with at least one DV that no longer matches — but this tool is meant as a fast warning sign, not a replacement for healthy suspicion: always confirm the bank shown here is the one from the original boleto you expected, especially if it arrived unexpectedly by email or WhatsApp.
The due-date factor and the 2025 change
On a bank slip, the due date isn't stored as a date — it's a 4-digit number (the "due-date factor") counting days since a fixed base date. Until 2025-02-21 the base date was 1997-10-07; that day the 4-digit counter hit its limit (9999), and FEBRABAN reset the factor to 1000 starting 2025-02-22, with a new base date (2022-05-29). That creates a permanent ambiguity for any factor of 1000 or higher — it can mean two very different dates, depending on which base date produced it. This tool always assumes the current base date (in effect since 2025) for those values, since that's the correct reading for virtually every boleto issued today.
Bank slip vs. collection/utility slip
There are two boleto formats with different layouts and check-digit algorithms. The bank slip is the common one — one person or company billing another — always module 10 on the field digits and module 11 on the general one. The collection/utility slip (water, power, phone, taxes) picks module 10 OR module 11 on a document-by-document basis, per a code embedded in the barcode itself — and its amount field sometimes represents an index-adjusted quantity/reference rather than currency directly. This tool recognizes both automatically from the digitable line's length (47 or 48 digits).
Frequently asked questions
No. A match only confirms the digitable line is mathematically well-formed — that no one mistyped it or altered a single digit after it was generated. It does NOT guarantee the beneficiary behind the bank/code shown is legitimate: a scammer can generate a perfectly valid, well-formed boleto with their own data. Always confirm the bank shown is the one you expected, and stay suspicious of unexpectedly received boletos even when every digit checks out.
Some collection/utility slips (value identifier "7" or "9" at barcode position 3) use the amount field as a quantity/reference adjusted by an issuer-defined index rather than a direct currency amount — typically bills whose total is only known at payment time (e.g. some variable-rate utility bills). This tool shows the raw number in that case, with a warning, instead of (incorrectly) formatting it as currency.
Unlike a bank slip, the FEBRABAN manual doesn't reserve a fixed barcode position for the due date on a collection/utility slip — when present, it lives in a free-use area whose position each bank/agency defines on its own. Without that guarantee, extracting a date would be guessing, not decoding; this tool would rather show nothing than show a wrong guess.
No. No digitable line pasted here ever leaves your browser — there's no network request and no server-side storage. All check-digit computation and bank/amount/due-date decoding happens locally, on your own device.
The barcode already carries 1 general check digit within its 44 digits. The digitable line adds 3 extra check digits — one per data block — so a cashier can type it in by hand when the optical scanner fails, without losing error detection: 44 barcode digits − 1 (the general DV, which becomes a standalone digit in the line) + 3 field check digits + 1 (the general DV repeated as its own field) = 47.
No — Nexinon deliberately keeps generation tools separate from verification/anti-fraud ones. This tool only decodes and validates an existing boleto; it never creates a new one.
Reading the PDF looks for text that already exists inside the file — the vast majority of boletos are generated digitally by the bank/fintech with real text, so this works for the overwhelming majority of cases. A scanned or photographed boleto (just an image inside the PDF, with no real text) has nothing to read that way; in that case, copy and paste the digitable line manually. The PDF never leaves your browser either way.
Because a name is free text — there's no check digit that can mathematically confirm "this is the right name", unlike a CNPJ/CPF, which has a real check digit (the same one the CPF/CNPJ Generator/Validator uses). This tool only shows PDF-extracted data when it can confirm it with certainty — never a "looks about right". Names stay out for that reason, not because the tool can't find them.
Unlike the barcode (position and format fixed by FEBRABAN), where the CNPJ/CPF sits in the PDF varies from bank to bank — each one lays out the document its own way. This tool looks for common labels ("Beneficiário"/"Cedente", "Pagador"/"Sacado") to know where to look, but only shows the number when it finds one AND its own check digit confirms it — never a guess.
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