Inspect a file's structure — before you repair anything

Sometimes the question isn't "how do I fix this" but "is this file actually broken?" These inspectors read a file's structure and tell you exactly what they find — valid or damaged, and if damaged, precisely where — without touching the file and without sending it anywhere.

Your file never leaves your device — inspection runs in your browser. 0 bytes uploaded.

What inspection is — and what it isn't

An inspector is read-only. It opens the file, walks its structure with the same parsers that drive IntactFile's repair engines, and prints a report: the container it detected, whether the key records are present and readable, and a table of the pieces inside — a ZIP's entries, a PNG's chunks — with the integrity check for each. It never rewrites bytes, never produces a "fixed" copy, and never uploads: the report is built entirely in your browser, which you can confirm with the Network tab open.

That makes it the honest first step. A file that "won't open" might be genuinely corrupt, or it might be perfectly valid and simply refused by one strict application, or it might not be the format its extension claims. Inspection settles which, so you don't pay for a repair you don't need — or waste time on a re-download when the bytes really are damaged. When repairis the answer, every inspector links straight to the matching repair tool, which starts from the very same diagnosis.

How to read a report

Each report opens with a one-line verdict and a short table of structural facts, then lists the findings in plain language. Below that, where it applies, is a developer-grade breakdown: for a ZIP, every entry with its method, compressed and uncompressed sizes, stored CRC-32 and pass/fail status, with any CRC or size mismatch spelled out; for a PNG, every chunk with its offset, length and CRC result. The wording is deliberately specific — "the central directory is missing", "IDAT chunk truncated", "CRC mismatch (expected …, got …)" — because a vague verdict helps no one.

The inspectors

ZIP inspector

ZIP · DOCX · XLSX · PPTX

Lists every entry with its compression method, sizes and stored CRC, integrity-checks each one, and shows the exact CRC or size mismatch when an entry is corrupt.

PDF inspector

PDF documents

Reads the %PDF- header, the trailer, the startxref pointer and the cross-reference table, and reports whether the document is intact, truncated, encrypted, or has a broken xref.

PNG inspector

PNG images

Verifies the 8-byte signature, reads the IHDR geometry, and walks every chunk checking its CRC — so a single flipped byte or a truncated IDAT is named precisely.

Once you know what's wrong

Repair it

If the file is genuinely damaged, therepair-tools index picks up from the same diagnosis and rebuilds the structure around the data that survived — still entirely in your browser.

Start from an error message

Staring at a specific code or message? Thefix-by-error index lists pages built around the exact text your software showed you.

Building or testing a repair tool?

The corrupted-file generatorcreates deliberately-broken ZIP, PDF, PNG and DOCX samples in your browser — reproducible fixtures to test how any inspector or repairer behaves against known damage.