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ESP Binary Inspector

Read an ESP firmware file without running it. See the target chip, data blocks and integrity checks locally in your browser.

Runs locally in your browser · no uploads or account
01 / LOCAL BINARY32 MiB MAX

Choose or drop one file. The worker reads it only in this page’s memory; nothing is uploaded or saved.

No file selected

Choose a local ESP binary to begin.

Background worker · local memory only

Supports documented 0xE9 bootloader/application images with at most 16 segments. It never executes firmware.

02 / FIRMWARE DETAILSREAD ONLY
Chip compatibility
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Entry point
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Flash header
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Integrity
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Secure boot / signatures
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SEGMENTS

#Load addressBytesFile offset

DOCUMENTED APPLICATION DESCRIPTION

WARNINGS & LIMITS

    LOCAL REPORT

    DOCUMENTED FIELDS ONLY

    Read the envelope.
    Keep uncertainty visible.

    Structure and integrity are separate.

    The inspector checks bounded segment records and the image XOR checksum. If the header says an appended SHA-256 digest exists, it validates that digest with Web Crypto. A valid checksum or digest shows byte-level consistency; it does not prove publisher identity, safe behavior, or board compatibility.

    Signature claims stop at the boundary.

    Trailing data may be a secure-boot signature or another extension. This tool reports it as ambiguous and does not claim to validate secure boot. The 0xE9 header also does not reliably distinguish bootloader from application images.

    Decoded application description strings appear only when the documented marker and complete structure are present. All strings are rendered as text. Checked arithmetic rejects truncated and overflowing segment ranges before data is read.