Preparing Documents for an Online Application: A Practical Checklist
Updated 5 October 2026 · 8 min read
Job, university, visa and government portals are strict about formats and sizes. Here is how to get every file accepted on the first try.
Online application systems are unforgiving. A photo that is 10 pixels too small, a PDF that is 50 KB over the limit, or a file in the wrong format is rejected, often with an unhelpful error, sometimes minutes before a deadline. Preparing your files properly beforehand turns submission into a five-minute job.
1. Read the requirements and write them down
Before touching any files, find the upload instructions and note, for each document:
- Accepted formats (PDF only? JPG or PNG?).
- Maximum file size, and sometimes a minimum.
- For photos: pixel dimensions, aspect ratio, background colour and how recent it must be.
- Whether several pages must be in one file or uploaded separately.
Requirements differ widely between organisations, so always follow the specific instructions over any general advice, including this guide.
2. Get the format right
| Asked for | What to do |
|---|---|
| PDF, but you have photos | Combine them with JPG to PDF |
| JPG, but you have a PNG | Convert with PNG to JPG |
| JPG, but your image is WebP or HEIC | Convert WebP with the WebP Converter; set iPhones to “Most Compatible” to shoot JPG |
| One PDF containing several documents | Join them with Merge PDF |
| A single page from a longer PDF | Pull it out with the PDF Page Extractor |
3. Get photos to the right dimensions
Photo requirements are usually given in pixels (for example 600 × 600) or as a print size (for example 35 × 45 mm). Check your photo with the Image Dimension Checker. If the shape is wrong, crop first with the Image Cropper, keeping the face centred with space above the head, then use the Image Resizer to hit the exact pixel size.
If you are given a print size, multiply each side in inches by the requested DPI, or, for millimetres, divide by 25.4 first. At 300 DPI, 35 × 45 mm is about 413 × 531 pixels.
4. Get under the size limit
Check the exact size with the Image File Size Checker. Note that many portals count 1 KB as 1024 bytes, and some as 1000, so aim a little below the limit.
- Photos and signature scans: resize to the required dimensions first; that alone usually solves it. If not, lower the quality with the Image Compressor. A passport-style photo at 600 × 600 pixels is normally well under 100 KB at good quality.
- PDFs: use Compress PDF and watch the live size as you move the slider.
Some portals also enforce a minimum size, for example “at least 20 KB”, to reject blank or broken uploads. If your file is too small, increase the quality or dimensions rather than padding the file.
5. Name files clearly
Use descriptive names without special characters: firstname-lastname-cv.pdf, transcript-bachelors.pdf. Some older systems reject spaces, accented letters or very long names, and clear names help the people reviewing your application.
6. Final check
- Open every file once more. Is it the right document, complete and readable?
- Is every page the right way up?
- Does each file meet the format, dimension and size rules you wrote down?
- Have you kept copies of everything you submitted?
Protect your personal data
Application documents are full of personal information: ID numbers, dates of birth, addresses, grades. Avoid uploading them to random online converters to resize or compress them. Every tool linked in this guide runs in your browser, so the files never leave your device.