View MOL files in your browser
Chemistry's most shared file for one molecule, from ChemDraw, RDKit, PubChem and every drawing app. Open a MOL right here in 3D. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your molecule opens in 3D, a protein's chains as a cartoon and a small molecule's atoms as balls and sticks, with its parts beside it and what you pick on the other side.
- Turn, zoom and move it • Double click to center on a point
- Cartoon, balls and sticks or spacefill • By element, chain or residue
- Inspect an atom • Its residue, chain, charge and B-factor
- Export • PNG, GLB, USDZ, STL and OBJ
About MOL
MDL Information Systems made the molfile for its chemical databases, and it became the file every chemistry app reads: ChemDraw, MarvinSketch, RDKit, Open Babel and PubChem's downloads all write it. A molfile is one molecule, and an SDF many.
It starts with three lines, the molecule's name, the program that made it and a comment, then a counts line, a line for each atom with its place and element, and a line for each bond with its order. The V3000 kind, for big molecules, writes the same in tagged lines.
Filepeek reads V2000 and V3000 in your browser and draws the atoms as balls and sticks, double and triple bonds drawn double and triple, or as spacefill, in each element's color. Click an atom for its element, charge and bonds, measure between atoms, and Export saves the view as PNG or the molecule as GLB, USDZ, STL or OBJ. A MOL saved flat, as ChemDraw and most sketchers save drawings, opens as its structure on white paper instead, a skeletal formula with its wedges and hashes, and saves as SVG, PNG or MOL.
MDL Molfile
.mol
Format
- MIME type
- chemical/x-mdl-molfile
- Made by
- MDL Information Systems
Inside the file
- Header
- Name, program and comment
- Atoms
- Place and element, one a line
- Bonds
- Two atoms and an order
- Kinds
- V2000 and V3000
Opens in every browser
Filepeek opens MOL files in 3D in Chrome, Edge, Firefox and Safari. On their own, browsers download them or show them as text.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open MOL
- WindowsNo app built in opens it • ChemDraw, MarvinSketch and Avogadro read it
- MacNo app built in opens it • ChemDraw, MarvinSketch and Avogadro read it
- iPhone and iPadNo app built in opens it • Save it here as USDZ to see it in your room
- AndroidNo app built in opens it • Save it here as GLB for 3D apps
Questions
Why does my MOL open as a drawing?
Most MOL files are drawings, saved with every atom at a depth of zero, as ChemDraw and most sketchers save them. Filepeek draws those as chemists do, a skeletal formula on white paper. A MOL with 3D coordinates, like PubChem's 3D conformers, opens in 3D.
What's the difference between V2000 and V3000?
V2000, the usual kind, fits at most 999 atoms and 999 bonds in its fixed columns. V3000 lifts that limit and writes each atom and bond on a tagged line. Filepeek opens both.
Why are there no hydrogens?
Many apps leave hydrogens out, as chemists know where they go. Filepeek draws only the atoms the file lists.
Can I save it for 3D printing?
Yes. Choose Export, then Save as STL or OBJ for the style on show, or GLB for 3D apps and USDZ for an iPhone or iPad.