# Replace the Google Chart QR code API (Developers)

URL: https://qrdx.dev/docs/developers/google-chart-api
Source: https://github.com/qrdxinc/qrdx/blob/main/apps/app/content/docs/developers/google-chart-api.mdx

QR codes from chart.googleapis.com now return 404. Map chl, chs and chld to the free QRdx image API, and update old URLs with one command.

Google deprecated its Image Charts in April 2012, and that included QR codes at `chart.googleapis.com/chart?cht=qr`. The endpoint now answers `404` (we checked on November 13, 2026), so old `<img>` tags, emails and spreadsheets that used it show a broken image.

The QRdx [image API](https://qrdx.dev/docs/developers/image-api) works the same way: a `GET` URL that returns the image, with no account or key. Change the host and rename three parameters.

## Before and after [#before-and-after]

```txt
https://chart.googleapis.com/chart?cht=qr&chs=300x300&chl=https%3A%2F%2Fexample.com&chld=M|2
https://api.qrdx.dev/v1/qr?format=png&size=300&data=https%3A%2F%2Fexample.com&level=M&margin=2
```

Both draw a 300 × 300 PNG of `https://example.com` at error correction M with a 2-module margin.

## Parameter mapping [#parameter-mapping]

| Google Chart | QRdx | Notes |
| --- | --- | --- |
| `cht=qr` | not needed | The endpoint only draws QR codes. Left in, it's ignored. |
| `chl=<data>` | `data=<data>` | URL-encoded the same way, up to 2048 characters. |
| `chs=<width>x<height>` | `size=<width>` | One number, because QR codes are square: `64` to `2048` pixels. |
| `chld=<level>\|<margin>` | `level=<level>&margin=<margin>` | The same letters, `L`, `M`, `Q` and `H`. The margin is in modules, `0` to `16`. |
| `choe=UTF-8` | not needed | QRdx always encodes text as UTF-8, which was Google's default. There's no Shift_JIS or ISO-8859-1 option. Left in, it's ignored. |
| always PNG | `format=png` | QRdx returns SVG unless you ask for `png`, `webp` or `eps`. Keep PNG for email, since many email clients don't show SVG. |

Two defaults differ. Without `chld`, Google used error correction `L`; QRdx uses `Q`, which survives more damage but makes a denser code. Add `level=L` if you need the old look. Both default to a 4-module margin.

## Migrate with one command [#migrate-with-one-command]

This rewrites every Google Chart QR URL in the files you name, including the older `chart.apis.google.com` host. It changes the host and path, renames `chl`, `chs` and `chld`, and adds `format=png` so the images stay PNG. Perl comes with macOS and most Linux distributions.

```bash
perl -pi -e 's{https?://chart\.(?:googleapis|apis\.google)\.com/chart\?([^\s"\x27<>)]*)}{my $q = $1; $q =~ s/(^|[&;])chl=/${1}data=/; $q =~ s/(^|[&;])chs=(\d+)x\d+/${1}size=$2/; $q =~ s/(^|[&;])chld=([LMQH])(?:\||%7C)(\d+)/${1}level=$2&margin=$3/i; $q =~ s/(^|[&;])chld=([LMQH])/${1}level=$2/i; "https://api.qrdx.dev/v1/qr?format=png&$q"}ge' index.html
```

Run it where you can review the change, such as a git checkout, and check the diff. To find the files that still use the old API:

```bash
grep -rlE "chart\.(googleapis|apis\.google)\.com/chart" .
```

A `chs` under 64 pixels (`50x50`) or over 2048 gets a `400` from QRdx, so change those sizes by hand.

## In code [#in-code]

```js
// Before
const src = `https://chart.googleapis.com/chart?cht=qr&chs=200x200&chl=${encodeURIComponent(link)}`;

// After
const src = `https://api.qrdx.dev/v1/qr?format=png&size=200&data=${encodeURIComponent(link)}`;
```

In Google Sheets:

```txt
=IMAGE("https://api.qrdx.dev/v1/qr?format=png&size=150&data="&ENCODEURL(A2))
```

Sheets loads images through Google's own servers, so a sheet with hundreds of codes can run into the per-IP limit below. For a big list, make the files once with the [bulk generator](https://qrdx.dev/tools/bulk) or the [CLI](https://qrdx.dev/docs/developers/cli)'s `qrdx batch`.

## What else to know [#what-else-to-know]

- **Rate limit:** 300 requests a minute per IP address. Over it you get `429` with a `Retry-After` header.
- **Caching:** the same URL always returns the same bytes, so responses are cached for a year (`Cache-Control: public, max-age=31536000, immutable`).
- **More options:** colors (`fg`, `bg`), module and eye shapes, a logo icon (`logoIcon`) and frames. Try them in the [URL builder](https://qrdx.dev/qr-code-api), or read the [parameters](https://qrdx.dev/docs/developers/image-api#parameters).
- **Self-hosting:** a [self-hosted](https://qrdx.dev/docs/self-hosting) QRdx serves the same API at `/api/v1/qr` on your own domain.