The headline and one figure
Somebody walking past reads two things. Decide now which two they are — everything else on the poster is for the people who stopped.
AI poster generatorAn AI poster generator for
An AI poster generator for
posters read from four metres away.
So it is built that way: one headline sized to stop somebody in a corridor, one figure they will remember, and the detail underneath for the people who came closer. The words are real text rather than painted text, and the best-quality export is 3240 px across — enough for a clean A3.
Water use · 2026
Most of it
never reaches
a tap
70%
of fresh water withdrawn worldwide
is used in agriculture
- Agriculture70%
- Industry19%
- Households11%
Illustrative figures · A4 to A2 · 3240 × 4050 px
Start to finish
How to make a poster with AI
- 1
Say what the poster is for
Paste the content, upload the paper or the notes, or describe the subject in a sentence. Name the audience and where it will hang — a corridor, a conference hall, a classroom wall.
- 2
Decide the two things read from four metres
The headline and one figure. Everything else on the poster is for the people who stopped walking, and the layout is built around that split.
- 3
Pick the proportion
Portrait suits A-series paper, long page suits a tall board, wide suits a landscape frame. Keep the proportion close to the paper you will print on.
- 4
Proof it at A4
Print one at quarter size before committing to A1. It costs nothing and catches the two faults that only appear on paper: a colour that shifted and a label that is too small.
- 5
Export the best-quality PNG and print
A portrait poster comes out at 3240 × 4050 px on a paid plan — about 390 DPI at A4 and 275 at A3. Leave the 10mm margin and send it.
Most AI posters cannot spell
Type “make me a poster” into an image generator and you get something that looks right in a thumbnail and falls apart at A2. That is not a flaw in the prompt. An image model paints a picture of a poster, letterforms included, so the text is decoration that happens to resemble words. For a decorative print that is fine. For anything anyone is meant to read and act on, it is the whole problem.
The words are typed, not painted
An image model draws something shaped like a letter. At poster size that is where the misspellings, the invented words and the wandering baselines show up — and a printed poster is the worst possible place to discover one. Here the text is text: set in a real typeface, spell-checked by you, and correct at any size.
You can fix it afterwards
A generated poster image is finished the moment it appears — a wrong date means starting over and hoping. Every piece here stays editable: change the date, swap a figure, correct a name, and reprint. The version history means a change you regret can be walked back.
The figures are yours, not plausible-looking
Image models invent numbers because they are drawing what a chart looks like rather than plotting data. The charts here are drawn from the figures you supplied, with their units and a source line, which is the difference between a poster that informs and a poster that decorates.
Design it for three distances at once
This is the whole discipline of poster design, and the reason a slide blown up to A1 never looks right.
The structure
Section headings, the chart shapes and the colour that separates them. This is the distance at which a reader decides whether to commit.
The detail
Labels, the method, the footnote, the source and the QR code or link to whatever the poster is a summary of.
Print sizes
The six sizes people actually print
Every A size is the same proportion, so one portrait sheet prints correctly at all of them. Letter and Tabloid are slightly wider, which usually means a little more margin rather than a redesign.
| Size | Millimetres | Inches | Typically for |
|---|---|---|---|
| A4 | 210 × 297 mm | 8.3 × 11.7 in | Handouts, noticeboards, a page in a pack |
| A3 | 297 × 420 mm | 11.7 × 16.5 in | Classroom and office walls — the most-printed size |
| A2 | 420 × 594 mm | 16.5 × 23.4 in | Corridors, waiting rooms, event boards |
| A1 | 594 × 841 mm | 23.4 × 33.1 in | Conference and research posters |
| US Letter | 216 × 279 mm | 8.5 × 11 in | North American handouts |
| Tabloid | 279 × 432 mm | 11 × 17 in | North American wall posters |
Five things that only go wrong on paper
- 01
Take the best-quality PNG, and know its ceiling
A portrait poster exports at 3240 × 4050 px on a paid plan. Fitted to the paper that is about 390 DPI at A4, 275 at A3 and 195 at A2 — all comfortable. At A1 it lands near 140 DPI, which large-format printers usually accept but which is the edge. There is no vector export, so A1 is the size to test rather than assume.
- 02
Leave a margin, and mean it
Nothing important within about 10 mm of the edge. Trimming is not exact, and a headline that touches the edge on screen can lose a letter in print.
- 03
Check the contrast on paper
Pale grey text that looks refined on a bright screen disappears under fluorescent light. Text on a poster should be near-black on near-white.
- 04
Set the type bigger than feels right
A poster is not a document. The body text on an A1 poster wants to be around 24pt; if it looks large on your laptop, it is probably correct.
- 05
Print one at A4 first
A proof at a quarter size costs nothing and catches the two mistakes that only appear on paper: a colour that shifted, and a label that is too small.
Four posters worth making
Research and conference posters
Question, method, results, limitation, conclusion — in that order, with the finding set large. Add a link or code to the full paper rather than trying to fit the paper on the wall.
Safety and process notices
Numbered steps with one action each, in words a tired reader can follow. If the poster needs a paragraph, it will not be read at the moment it matters.
Classroom and revision posters
One concept per poster. A timeline, a cycle or a comparison, in colours that separate the parts without turning into decoration.
Event and campaign boards
What, when, where, and the one number that makes the case. Everything else can live behind a link.
Printing questions
Can I print what it makes?
Yes, and the honest detail matters here. The file you print is a PNG: on a paid plan a portrait poster exports at 3240 × 4050 px, which works out at roughly 390 DPI at A4, 275 at A3 and 195 at A2. Those are all comfortable. A1 lands near 140 DPI — usually accepted for large format, read from a metre away, but it is the size to proof rather than assume. There is no vector export, so if your printer insists on a PDF or an EPS, take the PNG to them or print the share page to PDF from your browser.
Can ChatGPT make a poster?
It can produce an image that looks like a poster from across the room, and that is where it stops. The text inside is drawn rather than set, so headings come out misspelled, dates drift, and nothing can be corrected afterwards — you regenerate and hope. For a poster that only has to look like something, that is fine. For one that has to be read, printed and trusted, you want real type, editable content and charts drawn from your actual figures.
Can I make a research or conference poster?
Yes, and it is one of the better fits. Question, method, results, limitation and conclusion in that order, with the finding set large enough to stop someone in the aisle, and a link or code pointing to the full paper rather than trying to fit the paper on the wall. A1 is the usual size, and that is the one place to be careful: the best-quality PNG lands near 140 DPI at A1, which reads fine from a metre but is worth proofing at A3 first.
Can I add my own photos to a poster?
Yes. Upload your own images — PNG, JPEG, WebP, GIF or SVG, up to 8MB each — and place them in the piece alongside the type and charts. What it does not do is invent a photograph for you, which for an informational poster is usually the right trade: a decorative image tends to cost the space a label needed.
Can I set an exact poster size?
Not in millimetres. You choose the proportion — portrait, long page, square, wide or story — and the exported PNG is scaled to whatever paper you print it on. Keep the proportion close to the paper: a portrait sheet is 4:5 and A-series is closer to 1:1.41, so expect to trim a little or leave a wider margin at the sides.
What resolution is the output?
A portrait poster is composed on a 1080 × 1350 canvas and exported at double that on the free plan, triple on paid — so 2160 × 2700 px or 3240 × 4050 px. Always take the paid export for anything going to a printer, and never scale a standard one up: enlarging a PNG adds pixels without adding detail.
Is it free?
There is a free plan with no card required. Best-quality downloads and removal of the badge come with any paid plan, which is worth having before you send something to a print shop.
Do I need to sign up to make a poster?
Not to look around, and not to open a poster someone shares with you — those links need no account. Making your own needs a free account so the piece is saved and you can come back and correct it before printing, which matters more here than anywhere else. No card, and it takes a moment with Google.
Does it generate illustrations or photographs?
The sheets are drawn — type, charts, rules and figures — rather than photographic. That is deliberate for informational posters, where a decorative image usually costs space that a label needed.
Can I put my organisation’s logo on it?
Yes, through a brand kit: your logo, colours and typeface are applied to everything you make afterwards.
Print it once, and it works
Real type and real figures, at a resolution that survives the print shop.
Make a poster