PureRef is free and it floats. That is genuinely hard to beat.

Most comparison pages in this category are about two apps doing the same job. This one is not, and pretending otherwise would waste your afternoon. PureRef is a board that hovers over the thing you are making. Coii Ref is an index of the folders your references already live in, with boards on top of it. The overlap is the word "reference" and about forty per cent of a working day.

Start with the concession, because it is a large one. PureRef is pay-what-you-want for personal use — you can pay nothing — and the commercial tiers are $49 once for up to three users, or $10 per seat per month with $8 per seat billed yearly. It runs on Windows 10 or later, macOS 10.14 or later, and Linux. Coii Ref is $19 once, three Macs, and no other platform at all. If your entire need is a wall of images beside your canvas while you paint, PureRef does that better than we do, on more machines, for less money, and this page should end here for you.

What PureRef does not try to be is a library. Its handbook describes it as a minimal but powerful digital reference and mood board, and the features it documents are about the board: always on top, always on bottom, lock window, transparent to mouse, overlay mode, GIF playback, drawing, notes, groups, hierarchy, slideshow, grayscale, show colour code, show image coordinates. That is a precise and well-made set of tools for one job. None of them is a way to answer "which of the eleven thousand images on this drive are portraits I rated four or better and never filed".

Coii Ref exists for the second question and has boards so that answering it leads somewhere. Which of the two you need depends almost entirely on how big your pile is.

The table

Two rows in that table are the whole comparison. PureRef wins everything about the board itself. Coii Ref wins everything about the ten thousand images that are not on a board yet.

Where PureRef wins

It is the better window. Always on top is not a small feature dressed up; it is the reason people keep PureRef open for eight hours. Overlay mode, transparent to mouse and lock window are the refinements you get from a tool that has done one thing for years. Coii Ref is an ordinary application window. If your muscle memory is "references hover at the edge of the screen while I work", we do not replace that and are not trying to.

You can draw on it. PureRef documents drawing, notes, groups and hierarchy on the scene. Circling the bit of a photograph that matters, or drawing the line of action over a pose, is something people do constantly and Coii Ref cannot do at all. A Coii Ref canvas arranges images; it does not mark them up.

Free, for real, for personal work. There is no trial clock on a personal PureRef. That matters more than the sticker price: a student, or somebody who draws on Sundays, gets a complete tool for nothing, and the commercial tiers only start when money is involved.

Three platforms. Windows, macOS and Linux, from one download page. Coii Ref is a Mac app and there is no version of this argument where that changes.

It is one download and no setup. PureRef opens, you drag pictures in, and you are working. There is no index to build, no folder to nominate, no first pass to wait through. Coii Ref asks you to point it at a directory and let it read, and on a large drive that is a first run you start and leave. For a small working set, that setup is a cost with no return.

Grayscale, colour codes, coordinates, slideshow. These are the small tools of actually studying an image rather than filing it, and PureRef has more of them than we do.

Where Coii Ref wins

The thousands of images that never made it onto a board

The reason people end up with fourteen .pur files and a references folder of uncertain contents is that a board holds what you already found. Nothing in a board tells you what is on the drive. That is fine at two hundred images and becomes the central problem at ten thousand, which is roughly where anybody who has been collecting for five years now is.

Coii Ref points at the folders you have and reads them where they sit — dimensions, EXIF, colour — without moving, copying or renaming a single file. After that, the thing you have been scrolling for is one line away:

The keys are type ext tag rating is has no in width height added modified, AND across keys, OR inside a comma list, no parentheses. A word the parser does not recognise becomes free text rather than an error, so the grid never stops returning rows while you are mid-thought. Saved views store the text of a search and re-parse it on open, which is why renaming a tag does not break a view.

A board that is a file in your folder

A Coii Ref canvas is Something.coii-canvas: pretty-printed JSON, saved wherever you put it, listing which images sit where.

This is not a claim that PureRef will lose your scenes; it is a claim about what is checkable. PureRef's own handbook is clear about its format — the 2.0 file format saves images in their original format, and saving a newer scene as legacy format discards features such as drawings and groups. That is well-documented behaviour and exactly the kind of thing you want written down. The difference on our side is only that the file is text you can open in any editor tonight, without us, and that it names your images rather than carrying them, so the board is small and your originals stay the originals.

Everything the app writes lives inside your folder

Point Coii Ref at a directory and the index, the thumbnails and the canvas-resolution proxies are written inside it. Whatever backs that folder up has backed up the library. Copy the folder to another drive and the workspace goes too. Open it on your second Mac and there is no export step. Six drives is six self-contained workspaces rather than one application with opinions about which volumes it can see today.

The watcher is what keeps that honest. Filesystem events become the smallest re-scan that makes the index true again, so a rename in Finder is a rename rather than a new file with a lost rating, a moved folder is followed, and a drive that comes back after a month is reconciled instead of rediscovered. It keeps running after the trial ends, deliberately: an index that quietly rots is worse than no index.

Video is not a separate mode

Clips are picked up on the same index pass as stills, carry the same tags, ratings and notes, go onto a canvas beside the photographs, and are reachable from the same query line — type:video ext:mov is not something you switch into. Proxies are written at canvas resolution beside your files so a board of footage scrolls like a board of photographs. If half of what you collect is motion, that is worth trying against your own material during the trial.

Using both, which is what most people actually do

The honest recommendation for a lot of readers is not one of these. It is PureRef for the working session and Coii Ref for the drive.

The two do not fight, because Coii Ref never touches your files. Your references folders stay ordinary folders that PureRef can open. What changes is how you find the six images worth dragging in: instead of scrolling a Finder window, you run a query, look at the grid, and drag the ones you want. Coii Ref becomes the thing that answers "what have I got", PureRef stays the thing that floats beside the painting.

If you would rather not run two apps, the question is which half of the job is the bottleneck. If you always know where the picture is and the problem is having it visible while you work, that is PureRef and you should not pay us $19. If you have long since stopped knowing what is on the drive, an index is the only thing that helps and a board on its own will not.

The moment a board stops being enough

There is a fairly reliable point at which people go looking for something other than a board, and it is worth naming because it tells you whether you are at it.

It is not a number of images, though it correlates with one. It is the first time you know — with certainty — that you saved a particular picture, and you cannot find it. You remember the light in it. You may remember roughly when you saved it. What you do not remember is which folder, which drive, or which of the fourteen scenes you dragged it into, and twenty minutes later you give up and go looking for a new one on the internet instead. That is the moment. Everything a board does is still useful after it; it is just no longer sufficient.

The second symptom is subtler: you stop saving things. Collecting stops feeling like accumulation and starts feeling like burial, so you close the tab. A reference library that has quietly stopped growing is usually one that has outrun the tool holding it, and the fix is an index rather than more discipline.

If neither of those has happened to you, PureRef plus a sensible folder tree is a complete answer and you should not spend money on this. If both have, no amount of extra board features will help, because the missing capability is being able to ask a question about files you are not currently looking at.

Two files, and what each one is actually for

It is worth being precise about the formats, because "it saves a file" is true of both and the files do different jobs.

A .pur scene is the working document. It holds the arrangement you built and, per PureRef's own handbook, the 2.0 format saves images in their original format; saving a newer scene back to the legacy format discards features such as drawings and groups. It is a self-contained thing you can hand to somebody, and the handbook also documents that unsaved changes are kept in a temporary file and that periodic saving can be turned on with a default interval of five minutes.

A .coii-canvas is a description rather than a container. It is pretty-printed JSON naming which of your images sit where, so it stays small, your originals stay the single copy, and the file is legible to anything that reads text — version control, a diff, a script you write in an afternoon. The trade is the mirror image of PureRef's: a scene you can hand to somebody who does not have your files, against a board you can read, diff and regenerate but which needs the folder it describes.

Neither is better in the abstract. If you send boards to clients who do not have the images, the container wins. If you keep boards for years and want to be able to open one on a machine that has never had either app installed, the text file wins.

What neither of them does

Neither is a collaboration tool: no shared workspace, no comment thread, no live board a client opens in a browser. Neither has a mobile app, so a reference you find on your phone reaches your work the way it always did, by arriving in a folder later. Neither is an image editor. And neither is a backup — both of them are perfectly happy pointed at a drive with no second copy anywhere, and that remains your problem to solve with whatever you already use.

What switching costs

There is no PureRef importer. Coii Ref reads a refern library and nothing else, so a .pur scene does not come across as a canvas, and this page is not going to pretend that is a small thing if you have fifty of them.

What is genuinely easy is the images. PureRef exports — the whole scene as one image, selected images as one image, or all images as separate files in JPG, PNG, BMP or their original format, with optional cropping and a naming template. Export all images from the scenes you care about into folders, point Coii Ref at those folders, and the index has them in a first pass you start and walk away from. The layouts do not survive; the pictures do. For most people the layouts were disposable and the pictures were not, but you should decide that rather than find it out.

Nothing about this is destructive. Coii Ref does not move, copy or rename your files, so trialling it against a folder while you carry on using PureRef costs you nothing but disk space for thumbnails.

Who should use which

Use PureRef if you are on Windows or Linux; if the board needs to float over your painting software; if you draw or annotate on your references; if your working set is small enough that finding things has never been the problem; or if free-for-personal-use is the deciding factor, which is an entirely respectable reason.

Buy Coii Ref if you are on a Mac and the drive has got away from you; if you want ratings, tags, notes and EXIF searchable from one line; if you want boards that are plain files you can read and back up; if video is part of what you collect; and if $19 once for three machines is a fair price for turning a folder you dread opening into something you can query.

Worth reading next: the refern comparison, which is the one where we concede the most; Eagle if you want a full library that owns its files; Adobe Bridge, which is free and may already be installed; Apple Photos if your references and your photographs are the same pile; and Finder tags for the version of this that costs nothing at all. Otherwise, thirty days, every feature, no card and no account.