readelf.com
readelf.com client-side parserno upload4 tools readelf -h ./app

Client-side ELF inspection

Read the binary.
Not the error message.

Drop an ELF file into your browser and see what readelf would tell you — class, machine, sections, segments, symbols, NEEDED libraries, required GLIBC versions — plus the verdicts you normally derive by hand. Nothing is uploaded.

Open ELF Inspector Will it run here?
readelf -h ./app sample
Class
ELF64 · little endian
Type
ET_DYN · PIE
Machine
AArch64
Entry
0x00000000000c8f40
Interp
/lib/ld-linux-aarch64.so.1
Needed
6 shared libraries
Hardening
full RELRO · NX · canary
parsed in your tab 0 bytes uploaded

Sample output from a real aarch64 binary. The inspector reads the same fields straight from the file you drop in — and the file never leaves the tab.

Tools
4 · no account
Uploaded
never
Formats
32 / 64-bit · LE + BE
Libc
glibc · musl · static

Tools

4 instruments
inspect

ELF Inspector

Header, sections, segments, symbol tables, NEEDED libraries and security hardening flags. The readelf output you actually read.

32- and 64-bit, little and big endian / Symbol demangling (best effort) / Build ID and interpreter diagnose

Dependency Doctor

See exactly which shared objects a binary asks for, where it looks for them, and which ones your ldd output reports as missing.

NEEDED, RPATH and RUNPATH / Paste ldd output to diff / Static vs dynamic at a glance verify

Compatibility Checker

Will this binary run on that host? Compares architecture, word size, ABI and the required GLIBC symbol versions against your target.

x86-64, AArch64, ARMv7, RISC-V, s390x / glibc vs musl detection / Required GLIBC_x.y list extract

Strings & Symbols

Pull printable strings or the exported symbol list out of a binary without installing binutils — then filter them down to what matters.

Streamed, handles large files / Minimum length and substring filter / Copy or download as text

Guides

13 published
  1. cannot execute binary file: Exec format error — causes and fixes Why Linux refuses to run a binary with Exec format error, how to confirm the cause in three commands, and the five fixes that actually apply.
  2. version `GLIBC_2.34' not found — why copying libc never works How glibc symbol versioning works, why a binary built on a newer distribution refuses to start on an older one, and the four legitimate fixes.
  3. How to tell whether a binary is stripped (and what it costs you) What strip removes, what it leaves behind, how to confirm it with file and readelf, and how to get usable stack traces back from a stripped production binary.
  4. wrong ELF class: ELFCLASS32 or ELFCLASS64 — what it means The 32-bit versus 64-bit mismatch that shows up at link time and at dlopen time, why it is not the same as Exec format error, and how to resolve it.
  5. error while loading shared libraries: cannot open shared object file How the dynamic loader searches for libraries, why a library can be installed and still not found, and the five fixes that work in order of preference.
  6. How to check whether a binary is 32-bit or 64-bit (and for which CPU) Four commands that tell you the word size, instruction set and ABI of any executable — plus why file's one-line answer is sometimes all you need.

All 13 guides →

Why trust the numbers? Every field is read straight out of the file's own structures — no heuristics, no guesswork. Where a judgement is involved (is this binary PIE? is it fully RELRO?) the rule is documented on the methodology page, so you can verify any result with readelf -h on the same file.