Inchikey Format Validator

Validate the syntactic InChIKey block lengths and separators.

Description

An InChIKey is a compact hashed chemical identifier with uppercase blocks separated by hyphens.

An InChIKey is a compact hashed chemical identifier with uppercase blocks separated by hyphens. Checking its printed format cannot recover or validate the underlying molecular structure.^{[1, 2]}

Validate the syntactic InChIKey block lengths and separators.

When to use Inchikey Format Validator

Use this tool to validate the syntactic InChIKey block lengths and separators.

Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.

How to use Inchikey Format Validator and understand its results

Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.
Enter inchikey using the field table and calculation rules, then run the tool.
Read valid, connectivityBlock, stereoBlock. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
inchikey	Inchikey	string	Required

Enter text exactly; no trimming or case normalization is performed. Return validity, the 14-letter connectivity block and the whole 10-letter second block. Invalid text returns empty block placeholders.

valid=matches ^[A-Z]{14}-[A-Z]{10}-[A-Z]$

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
valid	Valid	boolean
connectivityBlock	Connectivity block	string
stereoBlock	Stereo block	string

json

{
  "input": {
    "inchikey": "AAAAAAAAAAAAAA-BBBBBBBBBB-C"
  },
  "output": {
    "valid": true,
    "connectivityBlock": "AAAAAAAAAAAAAA",
    "stereoBlock": "BBBBBBBBBB"
  }
}

Limitations and assumptions

The second returned block includes flags as well as hash text. No hash recomputation, structure decoding or registry lookup is supplied.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use SMILES Delimiter Validator: Check SMILES branch and atom-bracket balance; does not verify chemical valence. For a complementary task, use HMDB Accession Validator: Validate an HMDB accession against a caller-specified numeric width.

Further background: InChI Technical FAQ.

References

Inchikey Format Validator — tool.io
InChI Technical FAQ — InChI Trust

Similar or alternative tools

SMILES Delimiter Validator
Check SMILES branch and atom-bracket balance; does not verify chemical valence.
HMDB Accession Validator
Validate an HMDB accession against a caller-specified numeric width.