Last updated on 7 October 2026
You are preparing a session on ladders in CM2. The court plan is ready, it must come out at 1/100. You start printing, you put the ruler on the sheet: 9.4 cm where 10 was needed. The printer has ‘fitted to the page’ without asking you anything, and the exercise is running out of steam.
In short, printing a full-size image, with dimensions that you really choose, is surprisingly painful. GridPrint is a small free online tool that tackles this specific problem: you indicate the desired size in centimeters, he makes a PDF that respects it, on a sheet or on twenty. It is aimed at teachers who need a printed document to measure what it is meant to measure.
Table of Contents
What exactly is GridPrint?
A tool that runs in the browser, without installing anything. You deposit an image (JPG, PNG, SVG, WebP, TIFF...), you enter a width or height in centimeters, you choose your paper (A4 or A3, among others) and you retrieve a PDF. The image can come from anywhere: a scan, a photo, a poster exported from Canva.
If the requested size fits on a page, you get a page. If it exceeds, the image is spread over several sheets, with cut marks, an overlap area, numbered pages and an assembly plane.
Says like that, we immediately think of Rasterbator to create a giant poster, which I have presented here. However, the two tools do not start from the same question. Rasterbator transforms the image into a frame of dots and adjusts to the number of sheets: it is the tool of the spectacular poster. Here, the image remains clear, including text and strokes, and starts from a measurement in centimetres (we can also indicate a number of pages in width, if it is simpler). For a map or a pattern, it counts.
The history of the project amused me, by the way. Its author, the developer Luiz Tanure, recounts having created it for his tattooist companion, who was wasting a lot of time printing his stencils to the right size. We're far from the classroom...
Print a full-size image: the "two points" function
She stopped me by browsing the tool. The total size of the image is often unknown. We know only that of an element that is in it.
The "Set real size" function responds to this case. You mark two dots on the image, you indicate the actual distance that must separate them once printed, and GridPrint scales everything else. On the school plane, you point at the two ends of an 8-metre wall, you grasp 8 cm: the plan comes out at 1/100. On the silhouette of a royal eagle, you point at the tips of the wings and ask for about two metres. It doesn't matter if the photo is sideways or surrounded by emptiness.
According to the site, there are two additional safeguards: a scale rule printed in the PDF, on which a real rule to check is set, and a warning when the image does not have enough pixels for the requested size.
This second point deserves a judgment, because that is where many trials disappoint. An image caught on the web and then stretched over a meter will be blurred, regardless of the tool. The GridPrint FAQ provides a guide: around 300 DPI for what looks closely (a plan, a template), 150 DPI for a poster seen a few steps away. She also advises the PNG for line drawings and texts, the JPG for photos.
It remains a trap, and the tool can do nothing about it. When printing, choose “100 % or "real size" in the dialog box, never "fit to page". Otherwise return to square one.
What can be done in class
Working the ladders for real
In cycle 3 and college, this is the most direct use. The 1/50 class plan, a map snippet on a scale you set yourself, the neighborhood plan to prepare for an exit. Students measure on paper, calculate, and the result falls just because the document is right.
Same logic for a frieze where 1 cm is worth ten years. You prepare it with one of the tools to create chronological friezes, you export it as an image, and you take it out on three metres of corridor. To give an idea, the site advertises about seven A4 sheets in width for a two-metre banner.
Show life-size things
In science, the scale of a raptor, the footprint of a wolf, a banana leaf. In history, a museum object at its original size rather than as a thumbnail in the manual. In kindergarten, the silhouette of an animal next to which one comes to measure oneself.
I also think of students for whom numbers remain abstract, or who begin in French. Seeing that one metre eighty occupies almost the entire door says more than a conversion to the table.
Prepare a fresco or template
GridPrint embeds some effects, including contour detection and stencil mode. Only the following features are printed: much less ink, and a ready base for a collective fresco or giant colouring. In technology or plastic arts, you can take out a scale 1 template or pattern, to be carried over to the cardboard.
Appreciable detail when paper is counted: Empty pages can be excluded from the PDF before printing.
Is GridPrint really free?
Yeah, yeah. No account, no watermark, no paid version. The site even promises "free forever". I note the promise, knowing what these formulas are sometimes worth a few years later.
The interface exists in French (ten languages in total) and the tool is used from a browser, including on tablet or phone according to the site. I did not try it on a tablet. Once the page is loaded, it continues to work without a connection, and it can be installed as a web application. It works when the establishment’s Wi-Fi makes its own.
On the data side, the strong point is clear: Images are processed in the browser and are never sent to a server. You can therefore upload a class photo or student work without ulterior motives.
What I like, what I like less
What I like
- We reason in centimeters, with a control rule in the PDF to check.
- Simple, well-thought-out two-point scaling for plans and maps.
- No account, no sending of images: usable with students.
- Offline operation, once the page is loaded.
What I like less
- The tool only accepts images. A plan received in PDF will first have to be converted. And that, frankly, is a lack.
- The list of settings and effects is long, thought for creatives. I don’t know how young students are doing on their own.
- Cutting and gluing time does not disappear. Neither is the ink.
To be tested the next time a plan, map or template has to fall just: GridPrint.
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