---
id: KB-DI-002
url: https://app.codecontract.io/help/documents-and-ai/uploading-documents-and-taking-photos
idioma: en
categoria: documentos-ia
audiencia: usuario
actualizado: 2026-08-13
tambienEn: [es]
relacionados: [KB-DI-001, KB-PR-002, KB-TL-003]
citadoPor: [KB-DI-004, KB-DI-012, KB-CR-005, KB-DI-001]
enLaApp: https://app.codecontract.io/documents/upload
---

# Uploading documents and taking photos that read well

_Formats, size limit and the four mistakes that make a photo unreadable._

**Responde a:** how do I upload a document · photograph a document with my phone · the file is too large to upload · which formats can I upload · the document comes out skewed when photographed

A good share of the documents entering the platform are not PDFs: they are phone photos taken by someone on a building site, in a warehouse, or outside a notary's office. Whether that photo can be read comes down to four things, and all four are fixed at the moment it is taken.

**En corto**

- The limit is 30 MB per file, the same everywhere on the platform.
- Any format works for certifying; signing needs a PDF.
- From a phone, use the photograph option inside the link rather than attaching from the gallery.
- A 200 dpi scan reads just as well as 600 and weighs a fraction.

## The four things that ruin a photo

| Problem | What happens when read | How to fix it |
| --- | --- | --- |
| Shadow or backlight | Half the page goes dark and cannot be read | Stand with your back to the window, not facing it |
| Skewed document | Confidence drops on almost every field | The platform straightens it, but better to shoot it square |
| Blurry photo | Text comes out doubled and is not recognised | Rest the document on a table rather than holding it up |
| Cropped | Exactly the field you needed is missing | Frame the whole document with a little margin |

> [!NOTE]
> If the document has several pages, one photo per page beats one photo of two pages at once. A shot of a double spread reads badly almost every time.

## When the file is too large

Almost everything over 30 MB is a scan at unnecessarily high resolution. Rescanning at 200 dpi solves it without losing anything useful: it is more than enough for text, and the file drops to a fraction of the size. If it is a hundred pages, splitting it by section also makes things easier to find later.

## Frequently asked questions

**Which formats are accepted?**

For certifying, any: PDF, photo, spreadsheet, video, audio. Signing needs a PDF, and anything else is converted.

**Can I upload several documents at once?**

Yes. What is worth avoiding is putting different documents into one file: kept separate they are easier to find and to read.

**Is my original file modified?**

No. The original is kept exactly as it arrived. Anything generated — a reading, a signed PDF — sits alongside it.

**Can an external participant photograph from their phone?**

Yes, from the link itself, with nothing to install. It is the most common route and the one that works best.

## Ejemplos

**A site foreman photographs twelve delivery notes at the end of the day and half come out unreadable.**

- Rests them on the bonnet instead of holding them one-handed
- Stands with his back to the sun
- Takes one photo per note instead of two notes per photo

→ All twelve read first time and nobody has to go back to site to retake anything.

**The photo comes out blurred and cannot be read.**

- Retakes it with the document flat and good light

→ Reading improves without changing anything in the system.

**The photo is taken with a shadow across the text.**

- Changes position before shooting

→ The text comes out legible first time.

**A skewed scan is uploaded.**

- Rotates it before uploading

→ Automatic reading works.

**Several pages are photographed in one image.**

- Captures one page per image

→ Each page is read separately.

**The document has staples or folds covering text.**

- Flattens it before capturing

→ No text is missing from the reading.