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Learning hub
Most people arrive at a photo editor with a job, not a curriculum: crop a receipt, blur a name, get a file under 200 KB, make a passport photo. That is the right way to use a tool, and the tools index is built for it. But a job-by-job approach leaves gaps, and the questions that follow a first success are usually about why something behaved the way it did. This page is the other route. It groups the site's writing into four tracks, ordered so that each one assumes only what the previous track taught, and it ends with a glossary of the terms that cause the most confusion.
Nothing here is a course you have to finish. Pick the track that matches the problem in front of you, read the two or three lessons that apply, and go back to the editor. The tracks exist so that you can find the right explanation without guessing at search terms.
Track 1 — Start here: edit one image end to end
This track is for a first visit. It covers the whole loop — open, crop, adjust, annotate, export — on a single image, so that the interface stops being a wall of buttons.
| Lesson | What it teaches | Time |
|---|---|---|
| Crop, resize and mark up a screenshot | The core loop: crop to the useful region, annotate, export at the right size. | 8 min |
| Markup tools and precise placement | Arrows, shapes, highlight and text; zoom, pan and undo so placement is deliberate. | 10 min |
| How to annotate screenshots | What to point at, what to redact, and how to keep the evidence visible. | 7 min |
| Photo editing kaise kare (Hinglish) | The same loop explained in Hinglish for readers who prefer it. | 6 min |
Track 2 — Image fundamentals: why the result looks the way it does
Once the loop is familiar, the next questions are about quality: why an export looks blurry, why a gradient bands, why a file is unexpectedly large. This track explains the underlying mechanics rather than the buttons.
| Lesson | What it teaches | Time |
|---|---|---|
| Photo enhancement: light, crop and colour | Reading a histogram, fixing exposure, and when a filter makes things worse. | 12 min |
| Brightness and contrast, properly | What the two sliders actually do to pixel values, and why order matters. | 9 min |
| Why image text looks blurry | Resampling, compression artefacts and the difference between soft and small. | 8 min |
| Black and white editing | Luminance conversion versus desaturation, and when to threshold instead. | 10 min |
| File size versus quality | Where the bytes go and which lever actually moves them. | 9 min |
| Compression versus resizing | Why shrinking dimensions usually beats crushing quality. | 8 min |
Track 3 — Formats and file handling
Format decisions are where most avoidable damage happens: a transparent logo flattened onto black, a wide-gamut photo that shifts colour, a JPEG re-saved five times. This track is the reference for those choices, and it pairs with the supported-format matrix.
| Lesson | What it teaches | Time |
|---|---|---|
| JPG vs PNG vs WebP | The three formats that cover almost every web job, and how to choose. | 10 min |
| PNG transparency explained | Alpha channels, and what happens when a format has no alpha. | 8 min |
| Export resolutions and compression | Pixel dimensions, DPI, and preparing graphics for fast loading. | 11 min |
| Conversion checklist | A pre-flight list so a format conversion does not lose colour or transparency. | 7 min |
| Preparing images for the web | Sizing, naming and compression for a CMS or storefront. | 10 min |
| Preparing product images | Consistent backgrounds, ratios and crops across a catalogue. | 9 min |
Track 4 — Documents, PDFs and privacy
The last track covers the document side of the site: turning images into PDFs, splitting and merging them, getting under an upload limit, and removing the metadata that travels invisibly with a photo.
| Lesson | What it teaches | Time |
|---|---|---|
| Images to PDF for scans and receipts | Page order, page size and why a scanned PDF is not searchable. | 9 min |
| When to convert PDF to JPG | Rasterising versus keeping structure, and choosing a DPI. | 8 min |
| Splitting a PDF | Range syntax, page order and what happens to bookmarks. | 8 min |
| Merging PDFs safely | Order, encryption, signatures and the size consequences. | 9 min |
| Reducing PDF size for an upload limit | Working backwards from a byte ceiling without wrecking legibility. | 10 min |
| Removing photo metadata | EXIF, GPS, XMP and ICC — what to strip and what to keep. | 9 min |
| Is browser editing private? | What "local" does and does not protect you from. | 12 min |
Track 5 — Going deeper: the Photopea reference
For readers who want to understand a full professional editor rather than a focused utility, the site publishes a twenty-chapter, source-traced reference to Photopea. It is the deepest material here and it assumes no prior knowledge, but it is reference rather than tuition: read the overview first, then the chapters that match your work.
| Entry point | Why start there |
|---|---|
| Overview and five-minute verdict | What Photopea is, who it suits, and whether it replaces what you already use. |
| Limitations and decision guide | The honest list of gaps, so you can rule it in or out quickly. |
| The menu bar, item by item | Every command in the application, if you want the complete map. |
| The Photopea API | Embedding the editor in your own product, with the real protocol documented. |
Glossary: the terms that cause the most confusion
Resolution has two meanings that get mixed up. Pixel resolution is how many pixels wide and tall an image is. Print resolution, expressed in DPI, is how densely those pixels are packed onto paper. A file has one pixel resolution and can be printed at any DPI, so "300 DPI" is only meaningful once you also know the physical size.
Lossy and lossless describe whether saving a file discards information. JPEG and lossy WebP discard detail to save space, permanently, on every save. PNG, lossless WebP and TIFF keep everything, so repeated saves do not degrade the image.
Alpha channel is the fourth channel, alongside red, green and blue, that records transparency. PNG and WebP have one; JPEG does not, which is why transparency has to become a solid colour when you export to JPEG.
Bit depth is how many levels each channel can store. Eight bits gives 256 levels per channel, which is fine for screen work but can show banding in smooth gradients. Sixteen and thirty-two bit files store far more levels and are used for print and compositing.
Colour profile is a small embedded description of which colours a file's numbers refer to. sRGB is the safe default for the web. Adobe RGB and Display P3 cover a wider range but shift if the profile is dropped in conversion.
Metadata is everything in the file that is not pixels: camera settings, timestamps, GPS coordinates, copyright, editing history. It survives most conversions and is the main privacy risk in a shared photo.
Rasterising means turning vector or text content into pixels. It is one-way: once a PDF page is a JPG, the text is no longer text and cannot be selected or searched.
Banding is the visible stepping that appears in a smooth gradient when there are not enough levels to represent it, usually after an aggressive adjustment at eight bits per channel.