SMILES to Structure
Paste a SMILES string and visualize the 2D structure instantly using SmilesDrawer.
Open toolMolDraw Tools
All free chemistry tools now live in one central Tools Hub. Existing indexed tool URLs stay unchanged, so old bookmarks and Google results continue to work.
All tools are free and run in your browser. To draw chemical structures online, open the MolDraw editor, a free online ChemDraw alternative.
Use the central Tools Hub
The old free tools directory is kept for URL compatibility. Browse converters, calculators, 3D viewers, reaction drawing, TLC, and the periodic table from the main MolDraw Tools Hub.
Open MolDraw Tools HubStructure to SMILES
Draw a molecule in the 2D editor and get the SMILES string in realtime.
Open toolChemical Reaction Drawer
Draw chemical reactions online with reactants, products, arrows, reagents, conditions, and editable examples.
Open toolName to Structure
Resolve compound names to a 2D structure image, SMILES, formula, molecular weight, and PubChem CID.
Open toolMolecular Formula to Structure
Search molecular formulas such as C9H8O4 and compare multiple PubChem candidate structures.
Open toolSMILES to 3D Structure Converter
Render molecules in lightweight 3D and download PNG, JPG, SDF, XYZ, PDB, MOL, OBJ, and X3D formats.
Open toolXYZ / Gaussian to 2D Structure
Convert XYZ, Gaussian .gjf, or .com coordinate blocks into inferred 2D structure images with SVG, PNG, and MOL export.
Open toolXYZ to SMILES
Convert XYZ coordinate files into best-effort SMILES with inferred bonds and an editable cleanup canvas.
Open toolProtein Viewer (3Dmol.js)
Load proteins by PDB ID or local file, switch rendering styles, and export key file/image formats.
Open toolMOL to SMILES Converter
Convert MOL/SDF structure blocks to SMILES using a free web converter workflow.
Open toolSMILES to PDB Converter
Convert a SMILES string into a downloadable 3D PDB file for modeling workflows.
Open toolSMILES to PDBQT Converter
Convert a SMILES string to PDBQT for docking and AutoDock-style technical workflows.
Open toolPDB to PDBQT Converter
Transform raw PDB coordinate files into PDBQT format with browser-side conversion.
Open toolSMILES to InChI Converter
Generate standard InChI identifiers from SMILES strings for indexing and publication workflows.
Open toolSMILES to InChIKey Converter
Convert SMILES to compact InChIKey identifiers for database search and deduplication.
Open toolInChI to SMILES Converter
Convert InChI strings from papers and registries back into editable SMILES.
Open toolInChIKey to SMILES Converter
Resolve InChIKey values to canonical SMILES using public chemistry APIs.
Open toolSMILES to MOL Converter
Convert SMILES strings to MOL format for ELN/editor compatibility workflows.
Open toolSMILES to SDF Converter
Generate SDF output from SMILES for screening datasets and cheminformatics workflows.
Open toolPDB to SMILES Converter
Convert ligand PDB text blocks into SMILES in a best-effort conversion flow.
Open toolIUPAC Name to SMILES Converter
Convert systematic names into SMILES strings for structure-first workflows.
Open toolSMILES to IUPAC Name Converter
Generate IUPAC names from SMILES to support reports and publication writing.
Open toolMOL2 to SMILES Converter
Convert MOL2 ligand blocks to SMILES for normalization and data cleanup.
Open toolCID to SMILES Converter
Resolve PubChem CIDs to canonical SMILES using official PUG REST endpoints.
Open toolCAS Number to SMILES Converter
Convert CAS Registry Numbers to SMILES with PubChem metadata, formula, and molecular weight.
Open toolCAS Number to Structure
Look up a CAS number and display the matching 2D chemical structure with SMILES and CID.
Open toolSMILES to MOL2 Converter
Convert SMILES strings into MOL2 files for docking and ligand preparation workflows.
Open toolSDF to InChI Converter
Convert SDF/MOL structure blocks into standard InChI for indexing and data normalization.
Open toolSDF to InChIKey Converter
Generate InChIKey identifiers from pasted SDF or MOL blocks in one step.
Open toolInChI to InChIKey Converter
Convert full InChI strings into compact InChIKey values for faster search.
Open toolInChIKey to InChI Converter
Resolve InChIKey identifiers to full InChI strings using public chemistry APIs.
Open toolMOL to InChI Converter
Convert MOL/SDF text blocks into standard InChI for publication-ready identifiers.
Open toolMOL to InChIKey Converter
Convert MOL/SDF structures to compact InChIKey strings for registries and dedupe.
Open toolInteractive Periodic Table
Explore all 118 elements with searchable metadata including electron configuration, phase, and atomic mass.
Open toolSolution Prep Calculator
Compute solute mass required for your target molarity and final solution volume.
Open toolDilution Calculator
Apply C1V1=C2V2 to find stock volume and solvent volume for lab dilutions.
Open toolMolarity Calculator
Calculate molarity from mass, molecular weight, and final volume with a dedicated standalone tool page.
Open toolLimiting Reagent Calculator
Find the limiting reactant, excess reagent, leftover amounts, and theoretical yield from a balanced equation.
Open toolMolecular Weight Calculator
Calculate molecular weight, molar mass, element breakdown, and percent composition from formulas.
Open toolMolar Mass Calculator
Calculate molar mass with step-by-step working and convert grams to moles.
Open toolEmpirical Formula Calculator
Turn percent composition into the empirical and molecular formula, with steps.
Open toolProtein Molecular Weight Calculator
Sequence to average/monoisotopic MW in kDa, plus extinction coefficient at 280 nm.
Open toolStructure to IUPAC Name
Draw a molecule in the editor and get its IUPAC name instantly.
Open toolNet Ionic Equation Calculator
Complete and net ionic equations with spectator ions from solubility rules.
Open toolElectron Configuration Calculator
Full and noble-gas configurations for any element or ion, including Cr and Cu exceptions.
Open toolOxidation Number Calculator
Oxidation states of every element in a compound or ion, with step-by-step rules.
Open toolFormula and Mass Tools
Browse molecular weight, SMILES molecular formula, SMILES molecular weight, and exact mass tools in one cluster.
Open toolSMILES to Molecular Formula
Convert SMILES strings to molecular formula with PubChem metadata.
Open toolSMILES to Molecular Weight
Calculate molecular weight from SMILES and show formula and compound metadata.
Open toolExact Mass Calculator
Calculate monoisotopic exact mass from formulas for mass spectrometry checks.
Open toolMass Spectrum Predictor
Predict isotope pattern peaks, monoisotopic mass, average mass, and molecular ion region.
Open toolUV-Vis Spectrum Viewer
Open JCAMP-DX or CSV UV-Vis spectra in your browser. λmax, Beer-Lambert, colour, overlays and Tauc band gap.
Open toolRaman Spectrum Viewer
Open JCAMP-DX, CSV or SPC Raman spectra in your browser. nm to shift, baseline, spikes, smoothing, peaks and bands.
Open toolMass Spectrum Viewer
Open JCAMP-DX, CSV, mzML or mzXML mass spectra in your browser. Isotope pattern overlay, adducts, ppm error and neutral losses.
Open toolCyclic Voltammetry Viewer
Open CV files from CSV, CH Instruments, BioLogic, Gamry or Autolab. E1/2, ΔEp, ipa/ipc, reference conversion, HOMO/LUMO and Randles-Sevcik.
Open toolXPS Viewer
Open VAMAS, CasaXPS or CSV XPS spectra. Charge correction, Shirley background, peak fitting with doublets, atomic % and survey element ID.
Open toolTGA and DSC Viewer
Open TGA and DSC data from CSV, TA Instruments, NETZSCH or METTLER. DTG, step onset and mass loss, Tg, melting and crystallisation with ΔH, and % crystallinity.
Open toolIR Spectrum Viewer
Open JCAMP-DX, CSV or SPC IR spectra in your browser. %T or absorbance, baseline, peaks and functional groups.
Open toolNMR Viewer
Open JCAMP-DX, CSV or Bruker NMR files in your browser. Zoom, pick peaks, integrate and find solvent impurities.
Open toolSMILES to NMR
Predict 1H and 13C NMR chemical shifts from a SMILES string. This is a prediction, not an experimental spectrum.
Open toolStructure to NMR
Draw a structure and predict 1H and 13C NMR chemical shifts. The table is a model prediction, not a measured spectrum.
Open toolGrams to Moles Calculator
Convert grams to moles or moles to grams using formula-derived molar mass.
Open toolpH Calculator
Calculate pH, pOH, concentration, strong acid/base pH, buffer pH, and pKa values.
Open toolpKa Calculator
Calculate pKa from pH, pH from pKa, or buffer ratios with Henderson-Hasselbalch.
Open toolPercent Yield Calculator
Calculate percent yield, actual yield, or theoretical yield for chemistry labs.
Open toolLipinski Rule Calculator
Check Rule of Five properties from SMILES or compound names: molecular weight, LogP, HBD, and HBA.
Open toolDruglikeness Calculator
Calculate a simple Lipinski plus Veber-style druglikeness guideline score for compounds.
Open toolLogP Calculator
Retrieve PubChem XLogP from SMILES or compound names for quick hydrophobicity checks.
Open toolTPSA Calculator
Calculate topological polar surface area from SMILES or compound names.
Open toolLewis Structure Generator
Generate Lewis dot structures from molecular formula and charge, with SVG download.
Open toolVSEPR Molecular Geometry Calculator
Find the VSEPR shape, bond angles, hybridization and polarity of any molecule or ion, with a 3D model and full VSEPR chart.
Open toolAP Chemistry Score Calculator
Estimate your 1–5 AP Chem score from MCQ and FRQ points, with cutoffs and what you need for the next score.
Open toolHalf-Life Calculator
Radioactive decay and first-order kinetics: solve N, N₀, t or t½, with decay constant and chart.
Open toolIdeal Gas Law Calculator
Solve PV = nRT for P, V, n or T with unit conversions, plus combined, Boyle, Charles and Gay-Lussac laws.
Open toolTheoretical Yield Calculator
Balance a reaction, find the limiting reagent and calculate theoretical yield in grams, plus percent yield.
Open toolStoichiometry Calculator
Convert grams, moles, particles, gas litres or solution volume of one species into any other in a reaction, step by step.
Open tool3D Molecular Model Viewer
Search any molecule and rotate a ball-and-stick, space-filling or wireframe 3D model with CPK colours.
Open toolBuild a Molecule
Virtual molecular model kit: snap atoms together with valence checks, live formula, name and 3D, plus 20 challenges.
Open toolDegree of Unsaturation Calculator
Index of hydrogen deficiency from any formula (N, O, halogens, ions) or SMILES, with rings vs π bonds and steps.
Open toolIR Spectroscopy Chart
Interactive IR correlation table: look up a peak in cm⁻¹ and filter by functional group, with intensity and shape.
Open toolMolecular Formula Finder
Find formulas from an HRMS accurate mass (ppm, adducts, nitrogen rule, RDBE) or CHN elemental analysis.
Open toolSMILES Notation Guide
What SMILES is, every rule with examples, SMILES codes for common molecules and a live validator.
Open toolSpectroscopy Guides
How to read mass spectra, IR spectra and 1H/13C NMR spectra, with worked examples and quizzes.
Read guidesMolDraw Plugins
NMR Analyser, ChEMBL, MEP, Compare molecules, Protein viewer, Smart Draw and more, with screenshot guides.
Browse pluginsMolality Calculator
Calculate molality from solute amount and solvent mass for quick concentration checks.
Open toolChemical Equation Balancer
Balance molecular equations by element conservation with step-by-step guidance, presets, and technical background.
Open toolTLC Diagram Tool
Create standalone TLC plate diagrams with lanes, spots, Rf labels, and export options.
Open toolLast updated: