Polyfill.io

Usage and performance

The public instance of the polyfill service is hosted by the Financial Times, with the generous support of Fastly, who provide CDN distribution. View Fastly network map

Traffic volume

This shows the number of requests we have served per day, over the last 180 days, measured by Fastly:

DateRequests
26 Sep 2016 00:0030708594
27 Sep 2016 00:0030979031
28 Sep 2016 00:0030448237
29 Sep 2016 00:0033070611
30 Sep 2016 00:0030989258
1 Oct 2016 00:0026269919
2 Oct 2016 00:0026903843
3 Oct 2016 00:0031532742
4 Oct 2016 00:0031623831
5 Oct 2016 00:0031298294
6 Oct 2016 00:0032858436
7 Oct 2016 00:0030605979
8 Oct 2016 00:0028074666
9 Oct 2016 00:0026253609
10 Oct 2016 00:0031610214
11 Oct 2016 00:0031615384
12 Oct 2016 00:0032762516
13 Oct 2016 00:0035127124
14 Oct 2016 00:0031830945
15 Oct 2016 00:0025558341
16 Oct 2016 00:0026663325
17 Oct 2016 00:0031557804
18 Oct 2016 00:0032947258
19 Oct 2016 00:0033244866
20 Oct 2016 00:0035348101
21 Oct 2016 00:0028940846
22 Oct 2016 00:0026717800
23 Oct 2016 00:0026768761
24 Oct 2016 00:0032893166
25 Oct 2016 00:0031922615
26 Oct 2016 00:0030140887
27 Oct 2016 00:0027209311
28 Oct 2016 00:0022178026
29 Oct 2016 00:0019129258
30 Oct 2016 00:0021318060
31 Oct 2016 00:0023299931
1 Nov 2016 00:0024402896
2 Nov 2016 00:0026355258
3 Nov 2016 00:0025909551
4 Nov 2016 00:0023480946
5 Nov 2016 00:0020199931
6 Nov 2016 00:0022447545
7 Nov 2016 00:0028036560
8 Nov 2016 00:0030319676
9 Nov 2016 00:0035729277
10 Nov 2016 00:0028236920
11 Nov 2016 00:0023899624
12 Nov 2016 00:0020133392
13 Nov 2016 00:0022264924
14 Nov 2016 00:0027186467
15 Nov 2016 00:0030446593
16 Nov 2016 00:0030784832
17 Nov 2016 00:0029370094
18 Nov 2016 00:0026674972
19 Nov 2016 00:0022262511
20 Nov 2016 00:0025073502
21 Nov 2016 00:0031263002
22 Nov 2016 00:0030925019
23 Nov 2016 00:0029816114
24 Nov 2016 00:0027293499
25 Nov 2016 00:0026902168
26 Nov 2016 00:0022597621
27 Nov 2016 00:0024901236
28 Nov 2016 00:0032238266
29 Nov 2016 00:0031756367
30 Nov 2016 00:0031972402
1 Dec 2016 00:0030561717
2 Dec 2016 00:0025721499
3 Dec 2016 00:0022570148
4 Dec 2016 00:0023583934
5 Dec 2016 00:0029746317
6 Dec 2016 00:0028589146
7 Dec 2016 00:0028071204
8 Dec 2016 00:0027172091
9 Dec 2016 00:0025654051
10 Dec 2016 00:0023840512
11 Dec 2016 00:0027162970
12 Dec 2016 00:0029199457
13 Dec 2016 00:0030700233
14 Dec 2016 00:0028966255
15 Dec 2016 00:0027179634
16 Dec 2016 00:0023121747
17 Dec 2016 00:0019178732
18 Dec 2016 00:0020423247
19 Dec 2016 00:0025638517
20 Dec 2016 00:0030054247
21 Dec 2016 00:0027293125
22 Dec 2016 00:0028253934
23 Dec 2016 00:0025218199
24 Dec 2016 00:0020462590
25 Dec 2016 00:0019624526
26 Dec 2016 00:0025538280
27 Dec 2016 00:0028313547
28 Dec 2016 00:0027086156
29 Dec 2016 00:0026405218
30 Dec 2016 00:0024943598
31 Dec 2016 00:0021225557
1 Jan 2017 00:0020654814
2 Jan 2017 00:0025885081
3 Jan 2017 00:0029892864
4 Jan 2017 00:0030166919
5 Jan 2017 00:0030594723
6 Jan 2017 00:0029425708
7 Jan 2017 00:0025402726
8 Jan 2017 00:0025982172
9 Jan 2017 00:0032314246
10 Jan 2017 00:0031809252
11 Jan 2017 00:0032536835
12 Jan 2017 00:0032799886
13 Jan 2017 00:0029391192
14 Jan 2017 00:0025300299
15 Jan 2017 00:0027282852
16 Jan 2017 00:0032524907
17 Jan 2017 00:0032415786
18 Jan 2017 00:0033365658
19 Jan 2017 00:0035120602
20 Jan 2017 00:0041188974
21 Jan 2017 00:0030927077
22 Jan 2017 00:0029338687
23 Jan 2017 00:0034284932
24 Jan 2017 00:0034671031
25 Jan 2017 00:0035619948
26 Jan 2017 00:0036071213
27 Jan 2017 00:0032465983
28 Jan 2017 00:0026966448
29 Jan 2017 00:0029740069
30 Jan 2017 00:0036063509
31 Jan 2017 00:0036152486
1 Feb 2017 00:0038016618
2 Feb 2017 00:0038092744
3 Feb 2017 00:0036796339
4 Feb 2017 00:0032491273
5 Feb 2017 00:0032453018
6 Feb 2017 00:0036860319
7 Feb 2017 00:0035571731
8 Feb 2017 00:0036412197
9 Feb 2017 00:0036514897
10 Feb 2017 00:0033490604
11 Feb 2017 00:0027995607
12 Feb 2017 00:0029223036
13 Feb 2017 00:0036885381
14 Feb 2017 00:0035887992
15 Feb 2017 00:0038363219
16 Feb 2017 00:0038642420
17 Feb 2017 00:0034407156
18 Feb 2017 00:0028874822
19 Feb 2017 00:0030971428
20 Feb 2017 00:0037275115
21 Feb 2017 00:0038420294
22 Feb 2017 00:0037623473
23 Feb 2017 00:0039089757
24 Feb 2017 00:0036219130
25 Feb 2017 00:0034519605
26 Feb 2017 00:0035891521
27 Feb 2017 00:0043712007
28 Feb 2017 00:0045064797
1 Mar 2017 00:0045392374
2 Mar 2017 00:0046631873
3 Mar 2017 00:0042165614
4 Mar 2017 00:0037713394
5 Mar 2017 00:0039805594
6 Mar 2017 00:0046066982
7 Mar 2017 00:0045176879
8 Mar 2017 00:0044774385
9 Mar 2017 00:0047826146
10 Mar 2017 00:0045210137
11 Mar 2017 00:0037960796
12 Mar 2017 00:0038080093
13 Mar 2017 00:0044997769
14 Mar 2017 00:0044341787
15 Mar 2017 00:0045435363
16 Mar 2017 00:0046967559
17 Mar 2017 00:0043404160
18 Mar 2017 00:0038636175
19 Mar 2017 00:0040990946
20 Mar 2017 00:0046873678
21 Mar 2017 00:0046191872
22 Mar 2017 00:0054879586
23 Mar 2017 00:0051247835
24 Mar 2017 00:0043630492

Response time

Mean global response time, ms, from Pingdom:

DateResponse time (ms)
18 Mar 2017 04:00370
18 Mar 2017 05:00373
18 Mar 2017 06:00389
18 Mar 2017 07:00367
18 Mar 2017 08:00370
18 Mar 2017 09:00369
18 Mar 2017 10:00366
18 Mar 2017 11:00355
18 Mar 2017 12:00365
18 Mar 2017 13:00379
18 Mar 2017 14:00362
18 Mar 2017 15:00372
18 Mar 2017 16:00367
18 Mar 2017 17:00371
18 Mar 2017 18:00371
18 Mar 2017 19:00371
18 Mar 2017 20:00373
18 Mar 2017 21:00394
18 Mar 2017 22:00366
18 Mar 2017 23:00358
19 Mar 2017 00:00360
19 Mar 2017 01:00364
19 Mar 2017 02:00373
19 Mar 2017 03:00364
19 Mar 2017 04:00365
19 Mar 2017 05:00364
19 Mar 2017 06:00368
19 Mar 2017 07:00389
19 Mar 2017 08:00373
19 Mar 2017 09:00386
19 Mar 2017 10:00369
19 Mar 2017 11:00369
19 Mar 2017 12:00361
19 Mar 2017 13:00400
19 Mar 2017 14:00383
19 Mar 2017 15:00374
19 Mar 2017 16:00454
19 Mar 2017 17:00392
19 Mar 2017 18:00394
19 Mar 2017 19:00396
19 Mar 2017 20:00391
19 Mar 2017 21:00386
19 Mar 2017 22:00365
19 Mar 2017 23:00370
20 Mar 2017 00:00359
20 Mar 2017 01:00376
20 Mar 2017 02:00363
20 Mar 2017 03:00357
20 Mar 2017 04:00363
20 Mar 2017 05:00372
20 Mar 2017 06:00367
20 Mar 2017 07:00360
20 Mar 2017 08:00365
20 Mar 2017 09:00372
20 Mar 2017 10:00370
20 Mar 2017 11:00362
20 Mar 2017 12:00380
20 Mar 2017 13:00375
20 Mar 2017 14:00383
20 Mar 2017 15:00361
20 Mar 2017 16:00378
20 Mar 2017 17:00367
20 Mar 2017 18:00366
20 Mar 2017 19:00365
20 Mar 2017 20:00385
20 Mar 2017 21:00382
20 Mar 2017 22:00385
20 Mar 2017 23:00387
21 Mar 2017 00:00378
21 Mar 2017 01:00362
21 Mar 2017 02:00370
21 Mar 2017 03:00367
21 Mar 2017 04:00378
21 Mar 2017 05:00369
21 Mar 2017 06:00370
21 Mar 2017 07:00371
21 Mar 2017 08:00371
21 Mar 2017 09:00381
21 Mar 2017 10:00379
21 Mar 2017 11:00387
21 Mar 2017 12:00387
21 Mar 2017 13:00411
21 Mar 2017 14:00376
21 Mar 2017 15:00387
21 Mar 2017 16:00414
21 Mar 2017 17:00383
21 Mar 2017 18:00401
21 Mar 2017 19:00386
21 Mar 2017 20:00392
21 Mar 2017 21:00374
21 Mar 2017 22:00376
21 Mar 2017 23:00377
22 Mar 2017 00:00389
22 Mar 2017 01:00365
22 Mar 2017 02:00381
22 Mar 2017 03:00399
22 Mar 2017 04:00389
22 Mar 2017 05:00392
22 Mar 2017 06:00371
22 Mar 2017 07:00382
22 Mar 2017 08:00384
22 Mar 2017 09:00374
22 Mar 2017 10:00372
22 Mar 2017 11:00372
22 Mar 2017 12:00391
22 Mar 2017 13:00371
22 Mar 2017 14:00400
22 Mar 2017 15:00389
22 Mar 2017 16:00383
22 Mar 2017 17:00390
22 Mar 2017 18:00426
22 Mar 2017 19:00456
22 Mar 2017 20:00426
22 Mar 2017 21:00468
22 Mar 2017 22:00415
22 Mar 2017 23:00407
23 Mar 2017 00:00374
23 Mar 2017 01:00397
23 Mar 2017 02:00381
23 Mar 2017 03:00383
23 Mar 2017 04:00398
23 Mar 2017 05:00387
23 Mar 2017 06:00374
23 Mar 2017 07:00375
23 Mar 2017 08:00368
23 Mar 2017 09:00383
23 Mar 2017 10:00368
23 Mar 2017 11:00383
23 Mar 2017 12:00384
23 Mar 2017 13:00378
23 Mar 2017 14:00385
23 Mar 2017 15:00379
23 Mar 2017 16:00372
23 Mar 2017 17:00371
23 Mar 2017 18:00375
23 Mar 2017 19:00377
23 Mar 2017 20:00351
23 Mar 2017 21:00370
23 Mar 2017 22:00349
23 Mar 2017 23:00361
24 Mar 2017 00:00358
24 Mar 2017 01:00341
24 Mar 2017 02:00356
24 Mar 2017 03:00355
24 Mar 2017 04:00370
24 Mar 2017 05:00365
24 Mar 2017 06:00348
24 Mar 2017 07:00356
24 Mar 2017 08:00357
24 Mar 2017 09:00359
24 Mar 2017 10:00352
24 Mar 2017 11:00392
24 Mar 2017 12:00396
24 Mar 2017 13:00402
24 Mar 2017 14:00412
24 Mar 2017 15:00393
24 Mar 2017 16:00377
24 Mar 2017 17:00403
24 Mar 2017 18:00394
24 Mar 2017 19:00406
24 Mar 2017 20:00404
24 Mar 2017 21:00432
24 Mar 2017 22:00401
24 Mar 2017 23:00404
25 Mar 2017 00:00412
25 Mar 2017 01:00406
25 Mar 2017 02:00391
25 Mar 2017 03:00393
25 Mar 2017 04:00433

Caching

Hit ratio, last 7 days, from Fastly:

Cache resultRequests
Hits5179766755
Misses315870150

Availability

Total downtime, according to Pingdom:

Last 30 days18 minutes
Last 3 months18 minutes
Last 12 monthsan hour

Caching responses that vary by User-Agent is very hard to do with good cache performance. We use a custom Fastly VCL configuration that separates the UA normalisation from the polyfill bundle.

Network performance in detail

95th percentile and median resource timing metrics, broken down by Fastly edge point of presence, measured using the resource timing API from live polyfill service requests that opted in to anonymously report performance data. Last 30 days, showing only POPs that have served more than 10000 RUM-enabled requests.

PoP Sample Per connection phase (95th percentile and median) Overall
LCY 42,976
1,345ms
(162ms)
HHN 41,061
1,405ms
(202ms)
AMS 20,520
1,878ms
(211ms)
IAD 20,006
1,275ms
(74ms)
DFW 16,662
1,225ms
(103ms)
JFK 10,927
1,400ms
(113ms)
ORD 10,552
1,092ms
(105ms)

Only non-zero samples are counted, which in practice means there are far fewer DNS lookup and TCP connect datapoints, because if reusing a keep-alive connection, both will be zero. Timings for individual connection phases do not sum to the overall RTT because, for example, the request that exhibits the 95th percentile DNS time, will most likely not also be the 95th percentile on all other connection metrics.

Typically Polyfill.io is loaded at a point where the browser is very busy. To speed up loading, consider using preconnect or preload.