Free Diagonal Cell Grid Generator
Add a diagonal cell grid to any photo instantly with our 100% free generator. Upload a reference, choose slash or backslash per drawing, and every square halves for more accurate transfer, then export SVG or 600 DPI in seconds. No signup, no downloads needed. Trusted by 60,000+ artists worldwide.
One diagonal per cell
A square grid with a single diagonal struck through each cell, running one way. The diagonal gives every cell a second reference line, which is what makes a sloping edge easy to place inside a square.
5 controls, not a fixed picture
Set columns, rows and label size, choose diagonal direction, toggle cell labels. Every one is live on the canvas.
Stacks with draw & transfer
Overlays combine, each carrying its own transform, so this one can sit under or over square grid, rectangular and custom, and 4 more in the same set.
Guides that print with the ruling
The diagonals export as part of the grid at up to 600 DPI, or on their own on transparency. SVG keeps them as paths, so they stay clean at any enlargement.
| Ctrl + Z | Undo |
| Ctrl + Y | Redo |
| Esc | Deselect overlay |
| Alt + drag | Free positioning (no snap) |
| Ctrl + scroll | Zoom canvas |
| Ctrl + P | |
| ? | Show this help |
A transfer grid gives you cells. Adding one diagonal to each gives you triangles, and a triangle is a shape the eye judges far more accurately than a square.
The diagonal cell grid draws one of the 82 composition overlays in Grid Maker Pro, and the rest stack on the same image.
- 2 triangles per cell
- 45° only if square
- SVG + 600 DPI export
- Nothing uploaded
What is a diagonal cell grid?
The diagonal cell grid is a free browser tool that draws an even grid with a single diagonal in every cell, switchable between slash and backslash, halving each cell into two triangles. Columns and rows run to 50 each with optional labels. It draws over your own photograph, exports SVG and raster to 600 DPI, and never uploads anything.
How to use the diagonal cell grid
Square cells each crossed by one diagonal, which gives a curve two extra crossings per cell to be triangulated against. The standard grid, made twice as accurate.
Set the cell counts
A diagonal cell grid takes columns and rows to 50 each. Match the ratio to your canvas if you want square cells — the diagonal is only at 45° when the cell is square, and that requires the column-to-row ratio to equal the canvas's.
JPG · PNG · GIF · WEBP
Choose the direction
Slash or backslash. The choice is not cosmetic: the diagonal should run roughly with the dominant direction of what you are copying, so that contours cross it rather than lying along it.
Columns · Rows · Diagonal direction
Copy triangle by triangle, then export
Each cell is now two triangles and a contour crossing one has two edges and a hypotenuse to be measured against instead of four parallel sides. Export SVG or a raster up to 600 DPI.
PNG · JPG · PDF · SVG · up to 600 DPI
Three steps, about a minute. No signup, no upload.
What the Diagonal Cell Grid Generator does
Two triangles per cell
One diagonal halves every square. Where a square gives you four parallel edges to judge against, a triangle gives two edges and a hypotenuse at a different angle, which is a much richer set of references.
45° only when square
The diagonal's angle follows the cell's shape. On a square canvas at 8 × 8 it is 45°; on a 3:2 canvas at the same counts it is 33.69°, and on 16:9 it is 29.36°. Worth knowing before you use it as an angle reference.
Direction is a decision
Slash or backslash. Run the diagonal roughly with the subject's dominant direction and contours cross it cleanly; run it against and the contours lie along it, which tells you nothing at all.
Labelled cells
Optional A1-style labels, so a cell can be named rather than pointed at. As soon as more than one person is looking at the same grid, naming is what makes the conversation possible.
A hatching direction
For pen work, the diagonal doubles as a hatching guide: a consistent stroke direction across a whole drawing is what makes hatching read as tone rather than as texture, and consistency by eye is hard to keep for an hour.
Over your own reference
The diagonal earns its place on subjects with strong diagonal structure — a limb, a slope, a fold — where a square grid keeps cutting across the form at an unhelpful angle.
Diagonal cell grid examples: four ways the diagonal cell grid reads
Diagonal cell grid vs a plain square grid vs Cross-diagonal cells
| Option | Interior reference | Direction control | Vector export | Cost |
|---|---|---|---|---|
| Grid Maker Pro — diagonal cellsthis tool | One diagonal per cell | Slash or backslash | SVG + raster to 600 DPI | Free |
| A plain square grid | None | n/a | Yes | Free |
| Cross-diagonal cells | Two diagonals per cell | Both at once | Yes | Free |
| Halving the grid instead | More cells, no angles | n/a | Yes | Free |
Who a diagonal cell grid is for: subjects with a direction
How a diagonal cell grid works — The diagonal in the cell: why halving a square makes it easier to copy
A diagonal cell grid halves every square, which is the cheapest available improvement on the plain grid method — one of the 82 composition overlays that changes by one line. The method works because a small area is easier to judge than a large one, and adding a diagonal to each cell is the cheapest available improvement on it, and the reason is that triangles are easier to judge than squares.
Consider what you actually do inside a cell when you copy. A contour enters somewhere on the boundary and leaves somewhere else, and your job is to reproduce both crossing points and the shape between them.
On a plain square cell, the references available are four edges, all parallel to two directions, and four corners. A contour running at 30° to the horizontal has no edge to be compared with — you are estimating its angle against nothing.
Add a diagonal and the cell contains two triangles. Now a contour has three edges to relate to in each triangle, and one of them is at an angle unlike the frame's. Judgements of angle become comparisons rather than estimates.
Why triangulation beats a parallel edge
There is a second, subtler advantage. The eye is markedly better at judging whether a point lies on a line than at judging where along an empty span it lies. A diagonal gives every cell an interior line, so a contour crossing near it can be placed relative to a real reference rather than to a proportion of empty space.
Which is why triangulation is the standard technique in observational drawing generally: you do not measure a point's position, you locate it relative to two others by the angles between them. The diagonal is that technique built into the grid.
The angle of the diagonal is not always 45°
The angle of the diagonal deserves attention because it is not a constant. It runs corner to corner within the cell, so its angle is determined by the cell's proportions.
On a square cell it is 45°. On a canvas of any other proportion with equal column and row counts, it is not. At 8 × 8 on a 3:2 canvas the cells are 1.5 times as wide as tall, so the diagonal sits at 33.69° from the horizontal. On 16:9 the same counts give 29.36°.
That matters if you were planning to use the diagonal as a 45° reference — for a shadow direction, an isometric edge, a hatching angle. It is only 45° when the cells are square, which requires the column-to-row ratio to match the canvas's aspect ratio.
The diagonal cell overlay page covers the technique, beside the rest of the artist guide overlays. It also matters for the transfer itself. If your reference is gridded with square cells and your working surface with rectangular ones, the diagonals are at different angles at each end, and the mismatch is exactly the distortion that unequal cells always produce.
Choosing slash or backslash
The direction choice — slash or backslash — is genuinely a decision rather than a preference. The useful rule is that the diagonal should run roughly with the dominant direction of the subject.
The reason is that a contour lying along the diagonal tells you nothing: it coincides with the reference and gives you no crossing to measure. A contour crossing the diagonal at a good angle gives you a definite point, and the more nearly perpendicular the crossing, the more precisely you can locate it.
So for a subject running down and to the right — a slope, an arm, a fold in cloth — the backslash lies along it and the slash crosses it. Choose the crosser.
For subjects with no dominant direction, or with several, either choice works and the cross-diagonal version, which draws both, is the better tool.
Transfer work, and half-square triangles
The technique has a long history in transfer work, though it is less documented than the plain grid because it was a workshop practice rather than a written method. Diagonals appear in the underdrawing of a great many transferred cartoons, and their function is usually clear from context.
It also has a direct descendant in quilting, where the half-square triangle is one of the fundamental units. A square cut on the diagonal gives two triangles, and an enormous proportion of traditional pieced blocks are built from nothing else.
That connection is worth making because the quilting use runs the other way: the grid is not a copying aid but a construction, and the diagonal is where the fabric is cut. A diagonal cell grid at the right count is a cutting plan.
Hatching with a diagonal grid
For pen and ink work, the diagonal serves a third purpose that has nothing to do with transfer. Hatching reads as tone when the strokes are consistent in direction and as texture when they are not, and holding a consistent angle by eye across an hour of work is genuinely difficult.
A faint diagonal grid underneath gives a reference for every stroke, and the result is a much more even tone than most people can produce freehand. The grid is erased or ignored afterwards; its job was to keep the hand honest.
For cross-hatching specifically, the single diagonal is the first pass and the cross-diagonal grid is the second, which is the sequence the two overlays are designed around.
Labels, and a caution at high counts
The cell labels serve the same collaborative function they do on any transfer grid. A named cell is a shared reference, and the difference between a demonstration and a room full of people struggling separately is usually whether they can name what they are looking at.
For a plain grid the rectangular grid generator is the tool, and adding the second diagonal is what the cross diagonal grid generator does. The counts run to 50 in each direction, which is far more than most transfer work needs and about right for detailed pattern drafting. As with any transfer grid, the useful count is set by the smallest feature you must place — a cell smaller than a feature cannot tell you where the feature goes.
One practical caution: at high counts the diagonals add a great deal of line to the drawing, and over a mid-tone photograph the whole field can become hard to see through. Dropping the opacity a step below what you would use for a plain grid usually restores it.
The grid draws over your own image rather than exporting a fixed template because the direction decision depends on the subject. Which diagonal crosses your contours and which lies along them is a question about a specific picture.
The export sizes itself from the paper format and the DPI you choose rather than from your screen. SVG keeps every line editable, which matters when the grid is a cutting plan rather than a construction.
Everything runs in your browser. Images you load are never uploaded, because there is no server for them to reach. The drawing, the transform and the export all happen on your own machine.
Where a diagonal cell grid gets used
Choose the diagonal that crosses the contours, not the one that lies along them. A contour on the diagonal tells you nothing.
Half-square triangles are most of traditional piecing. At the right count the grid is a cutting plan, not a copying aid.
Holding a hatching angle by eye for an hour is hard. A faint diagonal underneath gives every stroke a reference.
Diagonal cell grid: frequently asked questions
The geometry
Why does a diagonal help when copying?
Two reasons. A triangle gives a contour three edges to relate to, one of them at an angle unlike the frame's, so judgements of angle become comparisons rather than estimates. And the eye is much better at judging whether a point lies on a line than where along an empty span it sits — the diagonal gives every cell an interior line.
Is the diagonal always at 45°?
Only when the cell is square. It runs corner to corner within the cell, so its angle follows the cell's proportions. At 8 × 8 on a 3:2 canvas it sits at 33.69°; on 16:9 at the same counts, 29.36°. Square cells need the column-to-row ratio to match the canvas's aspect ratio.
What if the subject has no dominant direction?
Either choice works, and the cross-diagonal grid — which draws both diagonals in every cell — is the better tool for that case.
Does the diagonal have to match between reference and surface?
Yes, and it matches only when the cells have the same proportions at both ends. Square cells on the reference and rectangular ones on the working surface put the diagonals at different angles, which is the same distortion unequal cells always produce.
What is the connection to quilting?
The half-square triangle — a square cut on its diagonal — is one of the fundamental pieced units, and a great many traditional blocks are built from nothing else. There the grid is a cutting plan rather than a copying aid, and the diagonal is where the fabric is cut.
How does it help with hatching?
Hatching reads as tone when the strokes are consistent in direction and as texture when they are not, and holding an angle by eye for an hour is genuinely hard. A faint diagonal grid underneath gives every stroke a reference and produces a far more even tone.
Using it
Which direction should I choose?
The one that crosses your subject's dominant direction rather than lying along it. A contour that coincides with the diagonal gives you no crossing to measure; one that crosses it at a good angle gives you a definite point. For a subject running down to the right, choose the slash.
What count should I use?
Set by the smallest feature the drawing has to place: a cell smaller than a feature says nothing about where the feature goes. The counts run to 50, which is more than most transfer work needs and about right for detailed pattern drafting.
It is hard to see the photograph underneath. What do I do?
Drop the opacity a step. The diagonals add a great deal of line at high counts, and over a mid-tone photograph the field can become hard to see through at the setting you would use for a plain grid.
Export and print
Can I print the grid to rule on my paper?
Yes. Set your paper format, leave the image off and export the grid alone — the printed sheet gives you the square grid and the diagonal in one pass, which is the tedious half of setting up by hand. At 600 DPI on A3 the lines stay fine enough not to swamp a small drawing.
Which format should I use to overlay it on a digital painting?
The transparent grid-only PNG. It carries the cells, the diagonals and the labels with nothing behind them, so it drops in as a layer above your canvas and can be hidden the moment you stop needing it. SVG if you want it to stay crisp while you zoom.
Choosing a grid
When should I use cross-diagonals instead?
When the subject has no dominant direction, or when you are working small and want maximum reference per cell. The cross-diagonal cell grid draws both diagonals, which gives you a centre point in every square and twice the interior structure — and twice the line density to see the photograph through.
Is a finer plain grid not the same as adding a diagonal?
No, and this is the useful distinction. Halving the grid gives you more cells, all with the same four parallel edges; the diagonal gives you an edge at an angle, which is the reference a parallel edge cannot provide. For contours that run obliquely, one diagonal beats four times as many squares.
Practical matters
Does anything I load get uploaded?
No. There is no server to upload to. The image is read by your browser, the grid is drawn on your machine, and the export is generated locally.
Can I use it to teach the grid method?
Yes, and the direction control is the teachable part — running the diagonal with the subject and then against it in the same lesson shows why it matters faster than explaining it does. Nothing is metered, so a class can each open their own.
Does it work offline once the page has loaded?
Yes. The page and the tool are cached by a service worker on first visit, so a return trip works without a connection — worth knowing if you draw somewhere with no signal.
Open the tool Diagonal cell grid
One line, every cell
Triangles instead of squares, in the direction you choose. Export vector or 600 DPI. No signup, nothing uploaded.
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