SMILES to SDF icon

SMILES to SDF

(1.0.0)

Generate 3D SDF files from SMILES strings with batch conversion and downloadable combined outputs. Learn more

SMILES to SDF icon

SMILES to SDF

(1.0.0)

Generate 3D SDF files from SMILES strings with batch conversion and downloadable combined outputs. Learn more

Related tools

SDF to SMILES

SDF to SMILES

Convert SDF ligand files, including multi-record batches, into SMILES strings.

format-conversionsmall-molecule+3
InChI to SMILES

InChI to SMILES

Convert InChI strings into SMILES with batch support and downloadable outputs.

format-conversionsmall-molecule+2
MOL to SMILES

MOL to SMILES

Convert MDL MOL ligand files into canonical SMILES strings for registration, filtering, and downstream analysis.

format-conversionsmall-molecule+2
MOL2 to SMILES

MOL2 to SMILES

Convert MOL2 ligand files into SMILES strings for registration, filtering, and downstream analysis.

format-conversionsmall-molecule+3
SMILES to InChI

SMILES to InChI

Convert SMILES strings into InChI strings with batch support and downloadable outputs.

format-conversionsmall-molecule+2
SMILES to MOL2

SMILES to MOL2

Convert SMILES strings into 3D MOL2 files for docking and molecular modeling workflows.

format-conversionsmall-molecule+3
SMILES to PDB

SMILES to PDB

Convert SMILES strings into 3D PDB files for molecular visualization and downstream docking preparation.

format-conversionsmall-molecule+3
Open Babel

Open Babel

Run Open Babel in the browser to convert chemical and structure files, with coordinate, hydrogen, and pH options where the WASM runtime supports them.

format-conversionsmall-molecule+4
PDB to SDF Converter

PDB to SDF Converter

Convert Protein Data Bank files to Structure Data Format

format-conversionsmall-molecule+2
SDF to PDB Converter

SDF to PDB Converter

Convert Structure Data Format files to Protein Data Bank format

format-conversionsmall-molecule+2
ProteinIQ
DashboardMy resultsProjectsNew
ToolsWorkflowsFiles

  • PDB Viewer
  • MSA Viewer
  • Molecule Drawer
AI Assistant
UsageSettingsSupport

Related tools

SDF to SMILES

SDF to SMILES

Convert SDF ligand files, including multi-record batches, into SMILES strings.

format-conversionsmall-molecule+3
InChI to SMILES

InChI to SMILES

Convert InChI strings into SMILES with batch support and downloadable outputs.

format-conversionsmall-molecule+2
MOL to SMILES

MOL to SMILES

Convert MDL MOL ligand files into canonical SMILES strings for registration, filtering, and downstream analysis.

format-conversionsmall-molecule+2
MOL2 to SMILES

MOL2 to SMILES

Convert MOL2 ligand files into SMILES strings for registration, filtering, and downstream analysis.

format-conversionsmall-molecule+3
SMILES to InChI

SMILES to InChI

Convert SMILES strings into InChI strings with batch support and downloadable outputs.

format-conversionsmall-molecule+2
SMILES to MOL2

SMILES to MOL2

Convert SMILES strings into 3D MOL2 files for docking and molecular modeling workflows.

format-conversionsmall-molecule+3
SMILES to PDB

SMILES to PDB

Convert SMILES strings into 3D PDB files for molecular visualization and downstream docking preparation.

format-conversionsmall-molecule+3
Open Babel

Open Babel

Run Open Babel in the browser to convert chemical and structure files, with coordinate, hydrogen, and pH options where the WASM runtime supports them.

format-conversionsmall-molecule+4
PDB to SDF Converter

PDB to SDF Converter

Convert Protein Data Bank files to Structure Data Format

format-conversionsmall-molecule+2
SDF to PDB Converter

SDF to PDB Converter

Convert Structure Data Format files to Protein Data Bank format

format-conversionsmall-molecule+2

Input

Configuration

10 credits

Output

Configure inputs to begin

Set options on the left, then click “Submit job”.

What is SMILES to SDF?

SMILES to SDF converts SMILES strings into three-dimensional SDF (Structure Data File) format using RDKit. SDF is the standard input format for most docking and cheminformatics workflows — while SMILES encodes connectivity, SDF carries 3D atomic coordinates that downstream tools require.

How to use SMILES to SDF online

ProteinIQ runs the conversion server-side, generating 3D coordinates without requiring RDKit or any other software to be installed locally.

Input

Paste one SMILES per line into the text area, or use name–SMILES pairs separated by a tab (name<TAB>SMILES). Free workspaces can convert up to 3 entries per job; paid plans support larger batches. Alternatively, upload .txt, .csv, .tsv, .smi, or .smiles files, or fetch compounds directly from PubChem by name or CID.

FormatExample
Bare SMILESCC(=O)Oc1ccccc1C(=O)O
Named SMILESaspirin\tCC(=O)Oc1ccccc1C(=O)O
File upload.smi, .smiles, .csv, .tsv, .txt
PubChem fetchCompound name or CID

Settings

SettingDescription
Add hydrogensAdds explicit hydrogens before 3D embedding (default: on). Required for accurate geometry and most docking pipelines.
Optimize geometryRuns a short UFF force field minimization after embedding (default: on). Improves coordinate quality for strained structures.

Output

Each entry produces an individual .sdf file. A combined batch.sdf containing all successfully converted structures is also generated for workflows that accept multi-record SDF input.

How it works

RDKit's AllChem.EmbedMolecule places atoms in 3D space using distance geometry, seeding initial coordinates from a random conformation. When Optimize geometry is enabled, Universal Force Field (UFF) minimization refines bond lengths, angles, and torsions. The resulting conformation is a reasonable starting geometry but represents a single local energy minimum, not necessarily the global one.

Limitations

  • Generates a single conformer per molecule. For ensemble docking or conformer sampling, generate multiple conformers separately.
  • Very large or highly flexible macrocycles can fail embedding — RDKit distance geometry struggles with long-range constraint satisfaction in these cases.
  • Tautomer and protonation state are taken as given from the input SMILES. Adjust ionization state before conversion if the target pH matters.

Table of contents